Solar Energy Materials and Solar Cells最新文献

{"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,&nbsp;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}

{"title":"Charge trapping, hydrogen accumulation, and structural rearrangement: A complete model for ultraviolet-induced degradation in TOPCon devices","authors":"Muhammad Umair Khan ,&nbsp;Alison Ciesla ,&nbsp;Aeron Johns ,&nbsp;Chandany Sen ,&nbsp;Ting Huang ,&nbsp;Hao Song ,&nbsp;Munan Gao ,&nbsp;Ruirui Lv ,&nbsp;Yuanjie Yu ,&nbsp;Xinyuan Wu ,&nbsp;Haoran Wang ,&nbsp;Xutao Wang ,&nbsp;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_x 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_it). We attribute this to high-energy UV photons breaking Si-H bonds within the SiN_x 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_x, which increases its negative fixed charge (Q_f). 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_it. Although the chemical passivation shows a full recovery, as confirmed by a decrease in D_it, 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}

{"title":"Performance enhancement of solar stills using evacuated tubes and pulsating heat pipes: A comprehensive review","authors":"Nagendra Prasad Pandey ,&nbsp;Yogesh kumar Sahu ,&nbsp;Rajshree Kokate ,&nbsp;Rakshit Parikh ,&nbsp;Abrar cinemawala ,&nbsp;Ravindra Gupta ,&nbsp;Haresh devjani","doi":"10.1016/j.solmat.2025.114148","DOIUrl":"10.1016/j.solmat.2025.114148","url":null,"abstract":"<div><div>Freshwater scarcity remains one of the most pressing global challenges, and solar stills (SS) have emerged as a sustainable solution for decentralized water purification. However, their limited productivity restricts large-scale deployment. Among the various enhancement techniques, the integration of heat pipes has demonstrated strong potential due to their highly efficient passive heat transfer capability. This review presents a comprehensive assessment of solar stills integrated with diverse heat pipe configurations including thermosyphons, pulsating heat pipes (PHP), loop heat pipes, and oscillating heat pipes and examines their performance when combined with phase change materials (PCM), nanofluids, photovoltaic/thermal collectors, condensation enhancement strategies, and finned basin designs. Notably, the integration of evacuated tube collectors (ETC), corrugated fins, and sensible heat storage materials has enabled freshwater yields up to 19 L/m²/day, while a nano-configured oil coupled with ETC achieved a 250 % increase in productivity, along with 242 % energy and 83 % exergy enhancement, reducing the cost per liter to 0.0101 USD/L and mitigating 131.97 tons of CO₂. Similarly, the incorporation of PHPs into solar stills resulted in yields of 8.7 L/m²/day, energy and exergy efficiencies of 64 % and 4.1 %, and CO₂ mitigation of 18.79 tons. A 4E framework Energy, Exergy, Economic, and Environmental is employed to systematically analyze these systems, offering comparative insights into yield, thermal efficiency, cost-effectiveness, and payback periods. Finally, the review highlights key research gaps related to material optimization, operational orientation, long-term reliability, and scalability, and proposes a future roadmap for developing cost-effective, high-performance, and environmentally sustainable solar still technologies.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114148"},"PeriodicalIF":6.3,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882641","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}

{"title":"Performance improvement of solar dish collectors with a helical receiver and ternary nanofluid","authors":"M. Sheikholeslami ,&nbsp;M.R. Bagheri","doi":"10.1016/j.solmat.2025.114146","DOIUrl":"10.1016/j.solmat.2025.114146","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study conducts a detailed computational analysis of modern solar heating configuration employing a parabolic dish reflector together with a coiled helical absorber, employing a ternary nanofluid. The dish concentrates solar radiation onto the receiver's focal point, where water infused with CoFe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;, TiO&lt;sub&gt;2&lt;/sub&gt;, and MgO nanoparticles provides enhanced energy absorption and superior thermal conductivity. The synergistic contribution of the three nanoparticles strengthens both photothermal conversion and heat transfer performance, while the helical receiver geometry promotes secondary flow patterns that intensify convective transport. To accurately represent the non-uniform solar irradiation across the receiver surface, solar flux distributions were generated using the SolTrace ray-tracing software and implemented in a 3D ANSYS FLUENT model through user-defined functions (UDFs). Turbulence and energy equations were applied to investigate thermohydraulic performance under various geometric and flow conditions. A parametric study explored the impact of coil turns (0–9) on thermal efficiency and pressure loss. The findings showed that additional turns enhanced heat transfer, yielding up to a 14.12 % increase in efficiency, but also caused a steep rise in pressure drop, up to 328.58 %. Beyond a threshold, efficiency gains saturated while hydraulic resistance continued to escalate, underlining the necessity for geometric optimization. To address this, a multi-objective optimization approach was implemented, balancing pumping requirements with thermal gains. Regression models based on Support Vector Machines were constructed to forecast the performance metrics, and the Weighted Sum Method (WSM) within Python software identified an optimal coil turn number of ∼2.3641. At optimized conditions (nanoparticle concentration of 0.03 and flow velocity of 0.15 m/s), the collector achieved a 14.05 % improvement in the Performance Evaluation Criteria (PEC). Increasing the flow velocity to 0.25 m/s delivered a maximum efficiency of 80.67 %, though PEC decreased by 3.68 % due to high Re (Reynolds number) effects. Receiver orientation was also examined, with the vertical position at 0.8 m above the dish yielding the highest absorption efficiency, representing an 11.68 % gain over a conventional straight-tube receiver. Based on the predicted annual thermal generation, the system can generate about $734.94 in yearly savings, enabling a rapid payback of around 10.6 months. Long-term operation provides additional economic benefit, with total profits approaching $3760 after six years. In summary, this work introduces a highly efficient and economically viable solar thermal configuration that combines ternary nanofluid technology, optimized helical receiver geometry, and advanced simulation-based analysis. It addresses a critical gap by linking receiver design to the thermohydraulic behavior of complex nanofluids under concentrated s","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114146"},"PeriodicalIF":6.3,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882629","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}

{"title":"Scalable cesium/potassium incorporation via CuGa:CsF/KF precursors enables high-efficiency selenized CIGSe solar cells","authors":"Lung-Hsin Tu ,&nbsp;Jun-Nan Liu ,&nbsp;Yung-Ling Chang ,&nbsp;Thung-Yu Tsai ,&nbsp;Ngoc Thanh Thuy Tran ,&nbsp;Rong-Zhi Chen ,&nbsp;Tzu-Ying Lin ,&nbsp;Shih-kang Lin ,&nbsp;Chih-Huang Lai","doi":"10.1016/j.solmat.2025.114151","DOIUrl":"10.1016/j.solmat.2025.114151","url":null,"abstract":"<div><div>This study explores the incorporation of alkali metals into Cu(In,Ga)Se₂ (CIGSe) thin films using CuGa:KF and CuGa:CsF sputtering targets, demonstrating their compatibility and scalability with industrial sequential processes without requiring any additional post-deposition treatment. The introduction of alkali metals through CuGa:KF and CuGa:CsF precursors significantly influences the compositional gradient, ordered vacancy compound (OVC) distribution, and cell performance. Ab initio calculations reveal a link between steeper Ga gradients and OVC formation. Co-doping with Cs and K, using a stacked precursor layer of sputtering CuGa:KF/CuGa:CsF targets, further optimizes the Ga gradient and reduces OVC formation at the backside of CIGSe. These effects collectively enhance cell performance, achieving an efficiency exceeding 17 %, even with low-reactivity Se vapor during selenization. This approach offers a new direction for simplifying heavy alkali metal incorporation and eliminates the need for post-deposition treatments. Importantly, it is fully compatible with existing industrial fabrication processes and provides a scalable pathway for high-efficiency selenized CIGSe production.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114151"},"PeriodicalIF":6.3,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882713","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}

{"title":"Solid-solid phase change films with intrinsic flexibility and photo-thermal conversion capabilities for human thermal management","authors":"Guangyu Zhu ,&nbsp;Jue Wang ,&nbsp;Wenxing Luo ,&nbsp;Wenjing Chen ,&nbsp;Yan Ma ,&nbsp;Xiongxin Jiang ,&nbsp;Qinglin Li ,&nbsp;Xiaowu Hu","doi":"10.1016/j.solmat.2025.114158","DOIUrl":"10.1016/j.solmat.2025.114158","url":null,"abstract":"<div><div>Phase change materials (PCMs) exhibit great potential for thermal energy storage; however, their practical applications are often hindered by leakage, intrinsic brittleness, and inefficient photothermal conversion. Herein, we present a simple and effective strategy for fabricating flexible phase change materials (NXPCMs) with intrinsic shape stability and photothermal conversion capability. The NXPCMs feature a typical linear polymer architecture with an internal physically crosslinked network. Synergistic covalent bonding, hydrogen bonding, and π–π stacking interactions endow the NXPCMs with outstanding leakage resistance, excellent mechanical performance (tensile strength of 15.83 MPa and elongation at break of 949.8 %), and high flexibility. Owing to the tunable polyethylene glycol (PEG) segments, the phase-change temperatures (40.1–50.9 °C) and latent heat values (93.89–131.3 J/g) can be effectively tailored within a desirable range. Notably, the limitations associated with conventional physical incorporation of photothermal fillers are overcome by embedding 1,5-dihydroxynaphthalene (DHN) directly into the polymer backbone, enabling simultaneous enhancement of photothermal conversion efficiency and mechanical integrity. As a result, the NXPCMs demonstrate excellent suitability for personal wearable thermal management. This work offers a promising strategy for the development of intrinsically photothermal PCMs for flexible wearable thermal management applications.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114158"},"PeriodicalIF":6.3,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882640","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}

{"title":"Effects of 5 MeV proton irradiation on flexible inverted metamorphic GaInP/GaAs/InGaAs triple-junction solar cells","authors":"T.B. Wang ,&nbsp;A. Aierken ,&nbsp;S.Y. Zhang ,&nbsp;M. Li ,&nbsp;X.B. Zhang ,&nbsp;J.S. Bi ,&nbsp;X.F. Liu ,&nbsp;M.Q. Liu ,&nbsp;C.S. Gao","doi":"10.1016/j.solmat.2025.114131","DOIUrl":"10.1016/j.solmat.2025.114131","url":null,"abstract":"<div><div>This study investigates the effects of 5 MeV proton irradiation on flexible inverted metamorphic GaInP/GaAs/InGaAs (IMM3J) triple-junction solar cells. Transmission electron microscopy (TEM) and cathodoluminescence (CL) analyses confirm that the flexible IMM3J solar cells possess high crystal quality. Based on SRIM simulations, 5 MeV protons penetrate the entire cell structure, producing nearly uniform damage, with vacancy defect density peaking near the bottom of the base region in each subcell. With increasing irradiation fluence, degradation in open-circuit voltage (<em>V</em>_oc) is more pronounced than that in short-circuit current density (<em>J</em>_sc). Analysis of the integrated current densities of the subcells reveals that the current-limiting junction shifts from the GaInP top cell to the InGaAs bottom cell as fluence increases. The degradation rate of the full-structure InGaAs subcell closely matches that of the complete IMM3J device, suggesting that damage in the InGaAs bottom cell plays a dominant role in determining overall current degradation. Dark-current curve fitting indicates that shunt resistance (<em>R</em>_sh) decreases while series resistance (<em>R</em>_s), diffusion current (<em>I</em>_s1), and recombination current (<em>I</em>_s2) increase with irradiation. Deep-level transient spectroscopy (DLTS) reveals no significant fabrication-induced defects. The most impactful irradiation-induced defect in the GaAs subcell is H1 (Ev+0.227 eV), while those in the InGaAs subcell are H2 (Ev+0.221 eV), H4 (Ev+0.547 eV), and H5 (Ev+0.558 eV).</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114131"},"PeriodicalIF":6.3,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882631","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}

{"title":"Photogating and electrical pulse erasure in SnO2-based synaptic transistors for non-volatile optical memory applications","authors":"Gexun Qin ,&nbsp;Yanmei Sun ,&nbsp;Xuelin Sun","doi":"10.1016/j.solmat.2025.114159","DOIUrl":"10.1016/j.solmat.2025.114159","url":null,"abstract":"<div><div>With the increasing demand for advanced optoelectronic memory and neuromorphic computing technologies, developing synaptic transistors capable of non-volatile optical storage and electrical modulation is crucial. In this study, we fabricate a SnO₂-based synaptic transistor with a bottom-gate top-contact structure, where SnO₂ serves as the primary conductive channel material. The device demonstrates bipolar transfer behavior with a high current switching ratio (1.05 × 10⁵) and long-term stability (&gt;8000 s). Under UV illumination (365 nm), the transistor exhibits a photogating effect, leading to persistent conductivity modulation due to trapped electrons forming localized electric fields. Additionally, the device shows synaptic functionalities, including excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), and transition from short-term plasticity (STP) to long-term plasticity (LTP) under optical pulses. Electrical pulse stimulation further enables tunable synaptic weight modulation, exhibiting pulse amplitude- and width-dependent plasticity. Notably, the device achieves non-volatile optical memory operation, where UV light pulses induce stable conductance states, and gate voltage pulses enable reversible erasure. However, performance degrades at elevated temperatures (&gt;35 °C), limiting high-temperature applications. These findings highlight the potential of SnO₂-based synaptic transistors for optoelectronic memory and neuromorphic computing systems.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114159"},"PeriodicalIF":6.3,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882767","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}

{"title":"Grafting engineering of ZIF-8 and polymer to enhance performance of gel electrolyte in electrochromic devices","authors":"Tian Li ,&nbsp;Dongxue Liu ,&nbsp;Sainan Ma ,&nbsp;Gang Xu ,&nbsp;Buyi Yan ,&nbsp;Xiaoyue Hao ,&nbsp;Likun Wang ,&nbsp;Yong Liu ,&nbsp;Gaorong Han","doi":"10.1016/j.solmat.2025.114143","DOIUrl":"10.1016/j.solmat.2025.114143","url":null,"abstract":"<div><div>As an indispensable and crucial component in electrochromic devices, transparent gel electrolyte has a significant impact on optical contrast, switching speed, cycling stability, and mechanical robustness. In this study, an engineering by grafting polar bimolecular groups of Terephthalic Dihydrazide (TPHD) onto the surface of ZIF-8 nanoparticles and polymer to enhance performance of gel electrolyte was proposed. Benefiting from the stable pore structure and high dispersion of TPHD modified ZIF-8 (TPHD@ZIF-8), the gel electrolyte doped with 6 wt% TPHD@ ZIF-8 (TGPL-6 %) achieves high initial transmittance of 82 % at 633 nm, representing a 23 % enhancement over the 6 wt% unmodified ZIF-8 doped gel polymer electrolyte layer (ZGPL-6 %). A high ionic conductivity of 1.73 mS/cm was obtained, which was 30 % higher than that of ZGPL-6 % (1.33 mS/cm) and more than four times that of pure GPL (0.37 mS/cm). Young's modulus and tensile strength of TGPL-6 % are 0.0064 and 0.179 MPa, respectively. The TGPL-6 % has been successfully applied in electrochromic devices, achieving a high optical modulation of 38 % and excellent durability. This work provides valuable insights into the rational design of high-performance transparent gel electrolytes for advanced electrochromic devices.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114143"},"PeriodicalIF":6.3,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145847598","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}

{"title":"Mitigating parasitic optical losses in bifacial TOPCon solar cells through localized thinning of polysilicon","authors":"Yalun Cai ,&nbsp;Shuo Deng ,&nbsp;Jialiang Huang ,&nbsp;Zicheng Wang ,&nbsp;Yuhao Cheng ,&nbsp;Jialin Cong ,&nbsp;Tang Qiao ,&nbsp;Geng Zhang ,&nbsp;Jian Song ,&nbsp;Feng Li ,&nbsp;Zhuo Xu ,&nbsp;Ning Song","doi":"10.1016/j.solmat.2025.114147","DOIUrl":"10.1016/j.solmat.2025.114147","url":null,"abstract":"<div><div>The parasitic absorption in the poly-Si layer on the rear side of a bifacial tunnel oxide passivated contacts (TOPCon) cell can compromise the short-circuit current density (J_SC) and cell efficiency. In this work, we demonstrate a local thinning (LT) approach on the polysilicon (poly-Si) layer in TOPCon cells to mitigate parasitic absorption. The LT approach is achieved by combining laser and alkaline etching. The 355 nm ultraviolet picosecond (UV-ps) pulsed laser introduces a 4 nm surface silicon oxide (SiO_X) which functions as an etch barrier in the subsequent alkaline etching. Consequently, lasered regions in the poly-Si layer can maintain a thickness of 110 nm while regions without laser treatment are thinned to about 30 nm. This local thinning process can suppress parasitic absorption while preserving excellent passivation. The laser also amorphizes the first 30 nm of the poly-Si into a-Si, which recrystallizes into poly-Si in later firing step with an increased doping concentration from 2E20 to 7E20 cm⁻³. Experimental J–V measurements show an increase in J_SC by 0.13 mA/cm², a V_OC gain of 1.9 mV, and an absolute efficiency gain of 0.12 % under one-sun illumination. Device-level simulations with Quokka3 further predict the efficiency gain of TOPCon cells incorporating this LT process under idealized contact and passivation conditions. These results highlight that the LT-TOPCon approach can effectively suppress rear-side parasitic absorption while maintaining passivation quality, offering a practical route to boost the efficiency of next-generation bifacial silicon solar cells.</div></div>","PeriodicalId":429,"journal":{"name":"Solar Energy Materials and Solar Cells","volume":"298 ","pages":"Article 114147"},"PeriodicalIF":6.3,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882766","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}