Pub Date : 2026-01-13DOI: 10.1016/j.solmat.2026.114170
Bernice Mae Yu Jeco-Espaldon , Aris C. Larroder , Dan Michael A. Asequia , Myeongok Kim , Erwin C. Sumarago , Jaedy V. Declarador , Stephen G. Sabinay , Noel Peter B. Tan , Yoshitaka Okada
Organic nanomaterials like nanocellulose offer sustainable advantages due to their renewability. Although nanocellulose is well-established in polymer reinforcement, its application as an anti-reflection coating in photovoltaic technologies remains underexplored. This study investigates Agave cantala nanocellulose–cyclic olefin copolymer (ACN-COC) composites as eco-friendly anti-reflection coating for III-V multijunction solar cells (MJSCs). Composite films with 0.10 % weight-to-volume (w/v) ACN concentration and 1.0 % w/v COC were prepared and coated to commercial MJSCs, resulting in an absolute 1.60 % increase in power conversion efficiency at unconcentrated, global air mass 1.5 standard illumination. This suggests that ACN-COC coatings are effective in reducing solar cell device's surface reflection. These findings highlight the promise of ACN-COC composites as eco-friendly coating that can boost solar cell performance and durability, paving the way for high-efficiency, next-generation sustainable photovoltaic technologies.
{"title":"Agave cantala nanocellulose – cyclic olefin copolymer composite as anti-reflection coating for III-V multijunction solar cell device","authors":"Bernice Mae Yu Jeco-Espaldon , Aris C. Larroder , Dan Michael A. Asequia , Myeongok Kim , Erwin C. Sumarago , Jaedy V. Declarador , Stephen G. Sabinay , Noel Peter B. Tan , Yoshitaka Okada","doi":"10.1016/j.solmat.2026.114170","DOIUrl":"10.1016/j.solmat.2026.114170","url":null,"abstract":"<div><div>Organic nanomaterials like nanocellulose offer sustainable advantages due to their renewability. Although nanocellulose is well-established in polymer reinforcement, its application as an anti-reflection coating in photovoltaic technologies remains underexplored. This study investigates <em>Agave cantala</em> nanocellulose–cyclic olefin copolymer (ACN-COC) composites as eco-friendly anti-reflection coating for III-V multijunction solar cells (MJSCs). Composite films with 0.10 % weight-to-volume (w/v) ACN concentration and 1.0 % w/v COC were prepared and coated to commercial MJSCs, resulting in an absolute 1.60 % increase in power conversion efficiency at unconcentrated, global air mass 1.5 standard illumination. This suggests that ACN-COC coatings are effective in reducing solar cell device's surface reflection. These findings highlight the promise of ACN-COC composites as eco-friendly coating that can boost solar cell performance and durability, paving the way for high-efficiency, next-generation sustainable photovoltaic technologies.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114170"},"PeriodicalIF":6.3,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.1016/j.solmat.2026.114162
Nayan Dev Madhavan , Anjitha Dinakaran , Favas K. Saneen , Ranjana Venugopal , Biswapriya Deb
Electrochromic devices (ECDs) offer dynamic control over solar radiation and daylighting, enabling significant energy savings in buildings. Optical haze (a measure of diffuse light scattering) is traditionally regarded as undesirable for conventional electrochromic devices (ECDs), limiting their potential for adequate privacy control. Here, we present a multifunctional ECD system that integrates tailored optical haze with electrochromic tinting to simultaneously deliver privacy, solar daylighting control, and a frosted-glass aesthetic. Multilayer WO3 films are fabricated by a scalable spray-coating process under controlled deposition conditions to yield tunable haze levels (3.4–14.5 %) through morphological control, as confirmed by SEM, AFM, and polarized light microscopy. The highest-haze device (H200) demonstrated a solar modulation efficiency (ΔTsol) of 63.6 %, better daylight spreading, more than 4 × haze enhancement upon coloration, and an 8.8 % reduction in visible-light-induced heat gain compared to a transparent counterpart. The unique microstructure, featuring bubble-like domains and tailored surface roughness, enables privacy even in the bleached state while maintaining solar transmittance. This approach offers a scalable, low-energy fabrication route for smart glazing that unites energy efficiency, glare reduction, and privacy control; a synergy addressing the increasing need for human-centric, climate-responsive building envelopes.
{"title":"Haze-engineered electrochromic WO3 smart windows for tunable solar modulation and privacy control","authors":"Nayan Dev Madhavan , Anjitha Dinakaran , Favas K. Saneen , Ranjana Venugopal , Biswapriya Deb","doi":"10.1016/j.solmat.2026.114162","DOIUrl":"10.1016/j.solmat.2026.114162","url":null,"abstract":"<div><div>Electrochromic devices (ECDs) offer dynamic control over solar radiation and daylighting, enabling significant energy savings in buildings. Optical haze (a measure of diffuse light scattering) is traditionally regarded as undesirable for conventional electrochromic devices (ECDs), limiting their potential for adequate privacy control. Here, we present a multifunctional ECD system that integrates tailored optical haze with electrochromic tinting to simultaneously deliver privacy, solar daylighting control, and a frosted-glass aesthetic. Multilayer WO<sub>3</sub> films are fabricated by a scalable spray-coating process under controlled deposition conditions to yield tunable haze levels (3.4–14.5 %) through morphological control, as confirmed by SEM, AFM, and polarized light microscopy. The highest-haze device (H200) demonstrated a solar modulation efficiency (ΔT<sub>sol</sub>) of 63.6 %, better daylight spreading, more than 4 × haze enhancement upon coloration, and an 8.8 % reduction in visible-light-induced heat gain compared to a transparent counterpart. The unique microstructure, featuring bubble-like domains and tailored surface roughness, enables privacy even in the bleached state while maintaining solar transmittance. This approach offers a scalable, low-energy fabrication route for smart glazing that unites energy efficiency, glare reduction, and privacy control; a synergy addressing the increasing need for human-centric, climate-responsive building envelopes.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114162"},"PeriodicalIF":6.3,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.1016/j.solmat.2026.114164
Chandany Sen , Haoran Wang , Robert Heidrich , Marius Lüdemann , Muhammad Umair Khan , Bram Hoex
N-type tunnel-oxide passivated contact (TOPCon) cell technology currently accounts for over 60 % of the PV market. Yet, its aluminium-rich front metallisation remains vulnerable to humidity-driven corrosion in glass/back-sheet modules. Building on our previous study, “Buyer Aware: Three new failure modes in TOPCon modules absent from PERC technology”, this work delves deeper into corrosion-induced degradation in TOPCon minimodules encapsulated with ethylene-vinyl acetate copolymer (EVA) and three commercially sourced polyolefin elastomers (POE-A, -B, and -C). After 1000 h of damp-heat exposure (85 °C, 85 % RH), the module with EVA showed a ∼11 %rel drop in Pmax, mainly attributed to a 50 %rel rise in series resistance (Rs). Spectroscopic analysis suggests that acetic acid released from EVA hydrolysis reacts with solder-flux residues, promoting front metal corrosion at the cell contacts. POE-A and POE-B modules degraded by only 6–10 %rel, neither produced measurable organic acids, and POE-A's antioxidant package appears to inhibit polymer oxidation, confining the residual loss to isolated pre-lamination contaminants. In contrast, POE-C suffered a 55 %rel in Pmax. Chemical probing reveals a potential cascade of mutually reinforcing reactions that generate a highly acidic micro-environment comprising: (i) carboxylic acids from POE oxidation, (ii) azelaic acid liberated from soldering flux, and (iii) benzoic and phenolic by-products from the ultraviolet (UV) absorber breakdown. This corrosive cocktail potentially accelerates the electrochemical attack on the front cell metallisation, driving a drastic Rs increase and catastrophic module failure. The study highlights the pivotal influence of encapsulant formulation, antioxidant, UV absorber chemistry and manufacturing cleanliness on the long-term reliability of TOPCon modules.
{"title":"The dark side of certain POE encapsulant: Chemical pathways to metallisation corrosion in TOPCon modules","authors":"Chandany Sen , Haoran Wang , Robert Heidrich , Marius Lüdemann , Muhammad Umair Khan , Bram Hoex","doi":"10.1016/j.solmat.2026.114164","DOIUrl":"10.1016/j.solmat.2026.114164","url":null,"abstract":"<div><div>N-type tunnel-oxide passivated contact (TOPCon) cell technology currently accounts for over 60 % of the PV market. Yet, its aluminium-rich front metallisation remains vulnerable to humidity-driven corrosion in glass/back-sheet modules. Building on our previous study, “Buyer Aware: Three new failure modes in TOPCon modules absent from PERC technology”, this work delves deeper into corrosion-induced degradation in TOPCon minimodules encapsulated with ethylene-vinyl acetate copolymer (EVA) and three commercially sourced polyolefin elastomers (POE-A, -B, and -C). After 1000 h of damp-heat exposure (85 °C, 85 % RH), the module with EVA showed a ∼11 %<sub>rel</sub> drop in P<sub>max</sub>, mainly attributed to a 50 %<sub>rel</sub> rise in series resistance (R<sub>s</sub>). Spectroscopic analysis suggests that acetic acid released from EVA hydrolysis reacts with solder-flux residues, promoting front metal corrosion at the cell contacts. POE-A and POE-B modules degraded by only 6–10 %<sub>rel</sub>, neither produced measurable organic acids, and POE-A's antioxidant package appears to inhibit polymer oxidation, confining the residual loss to isolated pre-lamination contaminants. In contrast, POE-C suffered a 55 %<sub>rel</sub> in P<sub>max</sub>. Chemical probing reveals a potential cascade of mutually reinforcing reactions that generate a highly acidic micro-environment comprising: (i) carboxylic acids from POE oxidation, (ii) azelaic acid liberated from soldering flux, and (iii) benzoic and phenolic by-products from the ultraviolet (UV) absorber breakdown. This corrosive cocktail potentially accelerates the electrochemical attack on the front cell metallisation, driving a drastic R<sub>s</sub> increase and catastrophic module failure. The study highlights the pivotal influence of encapsulant formulation, antioxidant, UV absorber chemistry and manufacturing cleanliness on the long-term reliability of TOPCon modules.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114164"},"PeriodicalIF":6.3,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-10DOI: 10.1016/j.solmat.2026.114165
Aseem Dubey , Ashmit Dubey , Akhilesh Arora
Conventional solar stills provide a sustainable solution to potable water scarcity but are limited by low productivity. To address the challenge, this study presents a novel hybrid solar still integrated with stearic acid as a phase change material (PCM) and an evacuated tube solar collector (ETC). A comprehensive energy–exergy–environment–economic (4E) assessment is conducted using a machine learning based prognostic framework. The proposed system achieves approximately 26.0 % higher yield than the system without PCM, although it produces about 3 % lower yield than the paraffin wax based system. The maximum productivity attained is 4.893 kg/m2, with corresponding energetic and exergetic efficiencies of 38.6 % and 3.22 %, respectively. For accurate yield prediction, feature relationships are examined using a pair-plot matrix and multiple machine learning models like Linear Regression, Decision Tree, Random Forest, Gradient Boosting Regressor (GBR), and XGBoost. Among them, the GBR model demonstrates superior performance with a high coefficient of determination (R2 = 0.9346), low mean square error (MSE = 0.0006), and strong Kling–Gupta efficiency (KGE = 0.9110). The 4E analysis indicates that considering environmental benefits, the water, energy, and exergy production costs range from 0.17 to 1.23 Rs./kg, 0.24–1.73 Rs./kWh, and 12.8–26.7 Rs./kWh, respectively, at interest rates of 2–10 %. Over a 20-year lifespan, the system mitigates 32.7 tCO2, with energy, exergy, and cost payback periods of 0.95, 3.3, and 1.6 years, respectively, establishing its sustainability and economic viability for remote applications.
{"title":"Machine learning based prognostic analysis of a hybrid solar still coupled with evacuated tube collector and stearic acid: A comprehensive 4-E assessment","authors":"Aseem Dubey , Ashmit Dubey , Akhilesh Arora","doi":"10.1016/j.solmat.2026.114165","DOIUrl":"10.1016/j.solmat.2026.114165","url":null,"abstract":"<div><div>Conventional solar stills provide a sustainable solution to potable water scarcity but are limited by low productivity. To address the challenge, this study presents a novel hybrid solar still integrated with stearic acid as a phase change material (PCM) and an evacuated tube solar collector (ETC). A comprehensive energy–exergy–environment–economic (4E) assessment is conducted using a machine learning based prognostic framework. The proposed system achieves approximately 26.0 % higher yield than the system without PCM, although it produces about 3 % lower yield than the paraffin wax based system. The maximum productivity attained is 4.893 kg/m<sup>2</sup>, with corresponding energetic and exergetic efficiencies of 38.6 % and 3.22 %, respectively. For accurate yield prediction, feature relationships are examined using a pair-plot matrix and multiple machine learning models like Linear Regression, Decision Tree, Random Forest, Gradient Boosting Regressor (GBR), and XGBoost. Among them, the GBR model demonstrates superior performance with a high coefficient of determination (R<sup>2</sup> = 0.9346), low mean square error (MSE = 0.0006), and strong Kling–Gupta efficiency (KGE = 0.9110). The 4E analysis indicates that considering environmental benefits, the water, energy, and exergy production costs range from 0.17 to 1.23 Rs./kg, 0.24–1.73 Rs./kWh, and 12.8–26.7 Rs./kWh, respectively, at interest rates of 2–10 %. Over a 20-year lifespan, the system mitigates 32.7 tCO<sub>2</sub>, with energy, exergy, and cost payback periods of 0.95, 3.3, and 1.6 years, respectively, establishing its sustainability and economic viability for remote applications.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114165"},"PeriodicalIF":6.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-10DOI: 10.1016/j.solmat.2026.114163
R. Moruno , L. San José , E. Luis , F. Martín , L. Dávila , R. Núñez , R. Herrero , I. Antón
This study evaluates the performance of a vehicle-integrated photovoltaic (VIPV) module under realistic dynamic shading along urban routes. A multistage framework combines image-based shadow extraction, irradiance and thermal modelling, and electrical simulation of two common interconnection schemes (series and total-cross-tied, TCT). Five routes covering different seasons and times of day were analysed, and four zone types—dense trees, scattered trees, open low-rise, and open midrise—were identified to contextualize shading behaviour. Results show that shading factor is the primary driver of performance losses, with winter routes exhibiting lower yield due to longer shadows despite cooler temperatures. TCT consistently outperforms series, particularly under highly non-uniform, dendritic winter shadows. Power spectral density analysis reveals that most power fluctuations occur below 24 Hz, enabling effective tracking by well-tuned P&O algorithms. Fixed-voltage control provides a strong baseline, while an artificial neural network evaluated on highly-dynamic sections offers modest improvements only in the TCT configuration.
{"title":"Comprehensive VIPV energy yield and MPPT evaluation under realistic dynamic shading in urban environments","authors":"R. Moruno , L. San José , E. Luis , F. Martín , L. Dávila , R. Núñez , R. Herrero , I. Antón","doi":"10.1016/j.solmat.2026.114163","DOIUrl":"10.1016/j.solmat.2026.114163","url":null,"abstract":"<div><div>This study evaluates the performance of a vehicle-integrated photovoltaic (VIPV) module under realistic dynamic shading along urban routes. A multistage framework combines image-based shadow extraction, irradiance and thermal modelling, and electrical simulation of two common interconnection schemes (series and total-cross-tied, TCT). Five routes covering different seasons and times of day were analysed, and four zone types—dense trees, scattered trees, open low-rise, and open midrise—were identified to contextualize shading behaviour. Results show that shading factor is the primary driver of performance losses, with winter routes exhibiting lower yield due to longer shadows despite cooler temperatures. TCT consistently outperforms series, particularly under highly non-uniform, dendritic winter shadows. Power spectral density analysis reveals that most power fluctuations occur below 24 Hz, enabling effective tracking by well-tuned P&O algorithms. Fixed-voltage control provides a strong baseline, while an artificial neural network evaluated on highly-dynamic sections offers modest improvements only in the TCT configuration.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114163"},"PeriodicalIF":6.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The need for sustainability and equitable use of resources is ever increasing because of global climate challenges and consequently, there have been increased efforts in the use of renewable energy sources like solar energy. The recycling of silicon kerf (sawdust), a waste material from the manufacture of solar wafers, is an important step in sustainability and circularity within the photovoltaic (PV) industry. The presence of carbon impurities in kerf presents challenges in the performance of the refined product in PV applications and thus it is important that it is reduced to acceptable levels. In this study a thermal oxidative decarburization of silicon kerf was conducted between 400 °C and 700 °C. Reaction mechanisms for the decarburization and simultaneous partial oxidation of silicon kerf particles were proposed based on the obtained results and effective decarburization of more than 90 % was achieved. Froth flotation was also conducted as an alternative low temperature route and under the conditions used was found not to be effective for decarburization of silicon kerf from diamond wire sawing due to limited selectivity at the very fine particle sizes of silicon kerf. The moderate temperature oxidative decarburization was therefore found to be effective for removal of carbon impurities.
{"title":"A comparative study on decarburization of silicon kerf through high temperature oxidation and froth flotation techniques","authors":"Tinotenda Mubaiwa , Chiedza Thelma Nzuma , Pshem Kowalczuk , Jafar Safarian","doi":"10.1016/j.solmat.2026.114171","DOIUrl":"10.1016/j.solmat.2026.114171","url":null,"abstract":"<div><div>The need for sustainability and equitable use of resources is ever increasing because of global climate challenges and consequently, there have been increased efforts in the use of renewable energy sources like solar energy. The recycling of silicon kerf (sawdust), a waste material from the manufacture of solar wafers, is an important step in sustainability and circularity within the photovoltaic (PV) industry. The presence of carbon impurities in kerf presents challenges in the performance of the refined product in PV applications and thus it is important that it is reduced to acceptable levels. In this study a thermal oxidative decarburization of silicon kerf was conducted between 400 °C and 700 °C. Reaction mechanisms for the decarburization and simultaneous partial oxidation of silicon kerf particles were proposed based on the obtained results and effective decarburization of more than 90 % was achieved. Froth flotation was also conducted as an alternative low temperature route and under the conditions used was found not to be effective for decarburization of silicon kerf from diamond wire sawing due to limited selectivity at the very fine particle sizes of silicon kerf. The moderate temperature oxidative decarburization was therefore found to be effective for removal of carbon impurities.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114171"},"PeriodicalIF":6.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-thermal-conductivity phase change materials (PCMs) are crucial for efficient solar thermal energy storage but often suffer from complex fabrication and high cost. Here, a cost-effective composite PCM with high latent heat and superior thermal conductivity was developed. A eutectic mixture of oxalic acid dihydrate and glutaric acid (OAD-GA, 30:70 mass ratio) was combined with 20 wt% expanded graphite (EG), yielding a PCM with a phase transition temperature of 67.9 °C and a latent heat of 197.7 kJ/kg. Incorporating layered graphite sheets (GS) enables the construction of directional thermal pathways, producing an OAD-GA/EG-GS0.6 composite with ultrahigh thermal conductivity (28.14 W/(m·K)) and outstanding reliability, showing only a 1.9% loss in latent heat after 500 cycles. The composite also achieved a high photothermal conversion efficiency of 91.1%, demonstrating strong potential for solar thermal storage and thermal management applications.
{"title":"Directionally structured oxalic acid dihydrate-glutaric acid/expanded graphite-graphite sheet composites with ultrahigh thermal conductivity for solar thermal storage","authors":"Sili Zhou , Junyi Niu , Wenbo Zhang , Shao Lin , Xiaoming Fang , Ziye Ling","doi":"10.1016/j.solmat.2026.114167","DOIUrl":"10.1016/j.solmat.2026.114167","url":null,"abstract":"<div><div>High-thermal-conductivity phase change materials (PCMs) are crucial for efficient solar thermal energy storage but often suffer from complex fabrication and high cost. Here, a cost-effective composite PCM with high latent heat and superior thermal conductivity was developed. A eutectic mixture of oxalic acid dihydrate and glutaric acid (OAD-GA, 30:70 mass ratio) was combined with 20 wt% expanded graphite (EG), yielding a PCM with a phase transition temperature of 67.9 °C and a latent heat of 197.7 kJ/kg. Incorporating layered graphite sheets (GS) enables the construction of directional thermal pathways, producing an OAD-GA/EG-GS<sub>0.6</sub> composite with ultrahigh thermal conductivity (28.14 W/(m·K)) and outstanding reliability, showing only a 1.9% loss in latent heat after 500 cycles. The composite also achieved a high photothermal conversion efficiency of 91.1%, demonstrating strong potential for solar thermal storage and thermal management applications.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114167"},"PeriodicalIF":6.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-09DOI: 10.1016/j.solmat.2026.114160
Xiaomao Xu , Liuxin Wang , Sijie Liu , Jintao Zhang , Xueli Mao , Xiaodan Fei , Yang Wu , Guo Pu , Fangfang Ge , Linjiang Chai , Bingsheng Li
Ni-based coating (15Fe16Cr63Ni) was fabricated via laser cladding on one surface of a 316L stainless steel substrate, while the opposing surface was subjected to laser remelting. This configuration created a macro-galvanic couple, which is representative of some practical scenarios where dissimilar materials are connected. The corrosion behavior of this coupled system in NaCl-MgCl2-KCl salts at 700 °C was investigated up to 1200 h. The results highlight a galvanic effect, while the Ni-coating was cathodically protected. Despite this coupling, a continuous Fe-Ni-rich layer formed in-situ on the coating surface, acting as a barrier. A critical finding is that even under the protective influence of galvanic coupling, the corrosion products and mechanisms for both sides evolved similarly, forming Mg2SiO4 beneath the Fe-Ni layer. A dedicated short-term (100 h) test with isolated, symmetrically treated specimens confirmed that the intrinsic corrosion rate of the Ni-coating is lower than that of the laser-remelted surface. Thus, the findings stress the paramount importance of mitigating galvanic coupling in design. The behavior observed suggests that the Ni-coating has considerable potential; however, verifying its long-term durability through testing under fully electrochemically isolated conditions remains an essential prerequisite for its reliable application.
{"title":"Corrosion behavior of laser-cladding nickel-based coating in high-temperature molten chloride salts","authors":"Xiaomao Xu , Liuxin Wang , Sijie Liu , Jintao Zhang , Xueli Mao , Xiaodan Fei , Yang Wu , Guo Pu , Fangfang Ge , Linjiang Chai , Bingsheng Li","doi":"10.1016/j.solmat.2026.114160","DOIUrl":"10.1016/j.solmat.2026.114160","url":null,"abstract":"<div><div>Ni-based coating (15Fe16Cr63Ni) was fabricated via laser cladding on one surface of a 316L stainless steel substrate, while the opposing surface was subjected to laser remelting. This configuration created a macro-galvanic couple, which is representative of some practical scenarios where dissimilar materials are connected. The corrosion behavior of this coupled system in NaCl-MgCl<sub>2</sub>-KCl salts at 700 °C was investigated up to 1200 h. The results highlight a galvanic effect, while the Ni-coating was cathodically protected. Despite this coupling, a continuous Fe-Ni-rich layer formed in-situ on the coating surface, acting as a barrier. A critical finding is that even under the protective influence of galvanic coupling, the corrosion products and mechanisms for both sides evolved similarly, forming Mg<sub>2</sub>SiO<sub>4</sub> beneath the Fe-Ni layer. A dedicated short-term (100 h) test with isolated, symmetrically treated specimens confirmed that the intrinsic corrosion rate of the Ni-coating is lower than that of the laser-remelted surface. Thus, the findings stress the paramount importance of mitigating galvanic coupling in design. The behavior observed suggests that the Ni-coating has considerable potential; however, verifying its long-term durability through testing under fully electrochemically isolated conditions remains an essential prerequisite for its reliable application.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114160"},"PeriodicalIF":6.3,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-09DOI: 10.1016/j.solmat.2026.114166
Hitoshi Sai, Takuya Matsui
Ultra-narrow strip-shaped crystalline silicon (c-Si) solar cells are promising for translucent photovoltaic modules but suffer from significant efficiency losses due to edge recombination after cell separation. An additional edge passivation process can alleviate this loss, but it increases cost and process complexity. This study investigates alternative approaches to suppress edge recombination loss without dedicated passivation layers. Strip-shaped silicon heterojunction (SHJ) cells, 3–9 mm wide, were fabricated using laser scribing and mechanical cleaving (LSMC). Experimental results, supported by device simulations, reveal that front-junction configurations and thinner c-Si substrates effectively mitigate efficiency loss associated with cut edges. Two additional design strategies were evaluated. A transparent conductive oxide (TCO) margin approach, which removes the emitter near the edge, improved open-circuit voltage to 715 mV in 5-mm-wide cells, although efficiency was constrained by reduced short-circuit current density. In contrast, the Pre-Grooved LSMC (PG-LSMC) method, enabling in-situ partial edge passivation, suppressed edge recombination and enhanced efficiency, particularly in rear-junction-type cells. These results highlight that optimized device design, thickness reduction, emitter isolation, and in-situ partial passivation can compensate for the absence of dedicated edge passivation. The insights gained from these extreme geometries are broadly applicable to divided and shingled cells, where edge recombination remains a critical loss mechanism.
{"title":"Ultra-narrow strip-shaped silicon solar cells for semi-transparent PV modules: Interplay among cut edges, cell structure, strip dimensions, and partial edge passivation","authors":"Hitoshi Sai, Takuya Matsui","doi":"10.1016/j.solmat.2026.114166","DOIUrl":"10.1016/j.solmat.2026.114166","url":null,"abstract":"<div><div>Ultra-narrow strip-shaped crystalline silicon (c-Si) solar cells are promising for translucent photovoltaic modules but suffer from significant efficiency losses due to edge recombination after cell separation. An additional edge passivation process can alleviate this loss, but it increases cost and process complexity. This study investigates alternative approaches to suppress edge recombination loss without dedicated passivation layers. Strip-shaped silicon heterojunction (SHJ) cells, 3–9 mm wide, were fabricated using laser scribing and mechanical cleaving (LSMC). Experimental results, supported by device simulations, reveal that front-junction configurations and thinner c-Si substrates effectively mitigate efficiency loss associated with cut edges. Two additional design strategies were evaluated. A transparent conductive oxide (TCO) margin approach, which removes the emitter near the edge, improved open-circuit voltage to 715 mV in 5-mm-wide cells, although efficiency was constrained by reduced short-circuit current density. In contrast, the Pre-Grooved LSMC (PG-LSMC) method, enabling in-situ partial edge passivation, suppressed edge recombination and enhanced efficiency, particularly in rear-junction-type cells. These results highlight that optimized device design, thickness reduction, emitter isolation, and in-situ partial passivation can compensate for the absence of dedicated edge passivation. The insights gained from these extreme geometries are broadly applicable to divided and shingled cells, where edge recombination remains a critical loss mechanism.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114166"},"PeriodicalIF":6.3,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.solmat.2025.114149
Muhammad Umair Khan , Alison Ciesla , Aeron Johns , Chandany Sen , Ting Huang , Hao Song , Munan Gao , Ruirui Lv , Yuanjie Yu , Xinyuan Wu , Haoran Wang , Xutao Wang , Bram Hoex
Tunnel oxide passivated contact (TOPCon) solar cells are susceptible to ultraviolet (UV)-induced degradation (UVID), which reduces their long-term performance. This study investigates the UVID mechanism in TOPCon lifetime structures with thin (4 nm) and thick (7 nm) AlOx layers. We use a cycle of UV exposure, dark storage, and dark annealing to track changes in chemical and field-effect passivation. During UV exposure, the chemical passivation degrades, shown by an increase in the interface defect density (Dit). We attribute this to high-energy UV photons breaking Si-H bonds within the SiNx capping layer, which releases mobile hydrogen that subsequently accumulates at the interface, thereby causing recombination-active defects. In contrast, the field-effect passivation is temporarily enhanced by charge trapping in the AlOx, which increases its negative fixed charge (Qf). A subsequent “dark storage degradation” occurs as these charges de-trap, while the chemical damage remains unchanged. During dark annealing, the accumulated hydrogen at the interface diffuses into the silicon bulk. This reduction in interfacial hydrogen concentration restores surface chemical passivation, as confirmed by a decrease in Dit. Although the chemical passivation shows a full recovery, as confirmed by a decrease in Dit, the FTIR analysis reveals that the complete degradation and recovery cycle induces a permanent structural rearrangement of the dielectric stack. Furthermore, the results show that the thicker 7 nm AlOx layer provides better UVID resilience. Since the field-effect passivation behaves similarly for both thicknesses, we attribute this resilience to the thicker film acting as a more effective physical barrier, reducing the transport of mobile hydrogen to the interface. This work presents a comprehensive model that links the observed UVID to specific, underlying structural changes in the passivation stack, providing guidance to address this failure mode at the solar cell level.
{"title":"Charge trapping, hydrogen accumulation, and structural rearrangement: A complete model for ultraviolet-induced degradation in TOPCon devices","authors":"Muhammad Umair Khan , Alison Ciesla , Aeron Johns , Chandany Sen , Ting Huang , Hao Song , Munan Gao , Ruirui Lv , Yuanjie Yu , Xinyuan Wu , Haoran Wang , Xutao Wang , Bram Hoex","doi":"10.1016/j.solmat.2025.114149","DOIUrl":"10.1016/j.solmat.2025.114149","url":null,"abstract":"<div><div>Tunnel oxide passivated contact (TOPCon) solar cells are susceptible to ultraviolet (UV)-induced degradation (UVID), which reduces their long-term performance. This study investigates the UVID mechanism in TOPCon lifetime structures with thin (4 nm) and thick (7 nm) AlO<sub>x</sub> layers. We use a cycle of UV exposure, dark storage, and dark annealing to track changes in chemical and field-effect passivation. During UV exposure, the chemical passivation degrades, shown by an increase in the interface defect density (D<sub>it</sub>). We attribute this to high-energy UV photons breaking Si-H bonds within the SiN<sub>x</sub> capping layer, which releases mobile hydrogen that subsequently accumulates at the interface, thereby causing recombination-active defects. In contrast, the field-effect passivation is temporarily enhanced by charge trapping in the AlO<sub>x</sub>, which increases its negative fixed charge (Q<sub>f</sub>). A subsequent “dark storage degradation” occurs as these charges de-trap, while the chemical damage remains unchanged. During dark annealing, the accumulated hydrogen at the interface diffuses into the silicon bulk. This reduction in interfacial hydrogen concentration restores surface chemical passivation, as confirmed by a decrease in D<sub>it</sub>. Although the chemical passivation shows a full recovery, as confirmed by a decrease in D<sub>it</sub>, the FTIR analysis reveals that the complete degradation and recovery cycle induces a permanent structural rearrangement of the dielectric stack. Furthermore, the results show that the thicker 7 nm AlOx layer provides better UVID resilience. Since the field-effect passivation behaves similarly for both thicknesses, we attribute this resilience to the thicker film acting as a more effective physical barrier, reducing the transport of mobile hydrogen to the interface. This work presents a comprehensive model that links the observed UVID to specific, underlying structural changes in the passivation stack, providing guidance to address this failure mode at the solar cell level.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114149"},"PeriodicalIF":6.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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