Pub Date : 2024-12-16DOI: 10.1109/JPHOTOV.2024.3496512
Kuan Liu;David C. Miller;Nick Bosco;Jimmy M. Newkirk;Tomoko Sakamoto;Reinhold H. Dauskardt
Degradation of photovoltaic (PV) module encapsulant characteristics that lead to mechanical embrittlement and delamination remains a cause of failure in solar installations. A multiscale reliability model connecting the encapsulant mechanical and fracture properties to the degraded molecular structure and interfacial bonding to adjacent solar cell and glass substrates was previously published. The model, developed primarily for poly(ethylene-co-vinyl acetate) acetate (EVA) encapsulants, remains to be experimentally validated. Determining the degradation and crosslinking kinetics of alternative encapsulants, such as polyolefin elastomer (POE) and EVA/POE/EVA composites (EPE), can generalize the model. In this work, we subject fully cured EVA, POE, and EPE encapsulants to accelerated thermal aging to determine how high temperatures impact reaction kinetics. An increase in gel content (crosslinking) and decrease in crystallinity of the encapsulants under hot-aerobic (90 °C, 22% RH) and hot-anaerobic (90 °C, sealed in N2 air) aging were observed, even in the absence of UV and crosslinking initiators. Fourier transform infrared spectroscopy (FTIR)-attenuated total reflectance analysis showed insignificant encapsulant degradation, demonstrating the critical role of UV and moisture in accelerating degradation. Adhesion testing performed on coupon-level specimens (cell/encapsulant/glass laminates) showed decreases in adhesion energy, Gc, from 5000 h of hot-dry (90 °C, ∼1% RH) and hot-humid (90 °C, 60% RH) aging. POE coupons demonstrated the best stability, followed by EPE then EVA. For EVA and POE, hot-humid aged coupons experienced a larger decrease in Gc due to enhanced hydrolytic degradation. Hot-dry aging condition demonstrated that thermal degradation of the interface could be significant even if the encapsulant experiences negligible degradation in the absence of UV and elevated humidity.
{"title":"Investigating the Crosslinking, Degradation, and Adhesion Behavior of Photovoltaic Encapsulants Under Thermal Accelerated Aging","authors":"Kuan Liu;David C. Miller;Nick Bosco;Jimmy M. Newkirk;Tomoko Sakamoto;Reinhold H. Dauskardt","doi":"10.1109/JPHOTOV.2024.3496512","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3496512","url":null,"abstract":"Degradation of photovoltaic (PV) module encapsulant characteristics that lead to mechanical embrittlement and delamination remains a cause of failure in solar installations. A multiscale reliability model connecting the encapsulant mechanical and fracture properties to the degraded molecular structure and interfacial bonding to adjacent solar cell and glass substrates was previously published. The model, developed primarily for poly(ethylene-co-vinyl acetate) acetate (EVA) encapsulants, remains to be experimentally validated. Determining the degradation and crosslinking kinetics of alternative encapsulants, such as polyolefin elastomer (POE) and EVA/POE/EVA composites (EPE), can generalize the model. In this work, we subject fully cured EVA, POE, and EPE encapsulants to accelerated thermal aging to determine how high temperatures impact reaction kinetics. An increase in gel content (crosslinking) and decrease in crystallinity of the encapsulants under hot-aerobic (90 °C, 22% RH) and hot-anaerobic (90 °C, sealed in N<sub>2</sub> air) aging were observed, even in the absence of UV and crosslinking initiators. Fourier transform infrared spectroscopy (FTIR)-attenuated total reflectance analysis showed insignificant encapsulant degradation, demonstrating the critical role of UV and moisture in accelerating degradation. Adhesion testing performed on coupon-level specimens (cell/encapsulant/glass laminates) showed decreases in adhesion energy, <italic>G<sub>c</sub></i>, from 5000 h of hot-dry (90 °C, ∼1% RH) and hot-humid (90 °C, 60% RH) aging. POE coupons demonstrated the best stability, followed by EPE then EVA. For EVA and POE, hot-humid aged coupons experienced a larger decrease in <italic>G<sub>c</sub></i> due to enhanced hydrolytic degradation. Hot-dry aging condition demonstrated that thermal degradation of the interface could be significant even if the encapsulant experiences negligible degradation in the absence of UV and elevated humidity.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 2","pages":"309-319"},"PeriodicalIF":2.5,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-04DOI: 10.1109/JPHOTOV.2024.3507079
António J. N. Oliveira;Bin Du;Kevin D. Dobson;Jennifer P. Teixeira;Maria R. P. Correia;Pedro M. P. Salomé;William N. Shafarman
The conversion efficiency of CdTe solar cells may be improved by bandgap engineering, i.e., changing the bandgap value through the addition of Se in the absorber. The Se alloying enables a short-circuit current density improvement, as it leads to a bandgap energy value decrease. Furthermore, it has been associated with increased minority carrier lifetimes, assuring high open-circuit voltage values. An Se gradient profile control can further optimize the solar cell performance. Thus, an optical model baseline of the CdSexTe1−x (CST) compound was developed. Spectroscopic ellipsometry measurements were conducted to accurately extract the optical constants of ten CST layers deposited through coevaporation with x varying from 0 to 1. Using the measured dielectric function spectra from the discrete CST layers with varying x, and considering the composition-induced shift in the critical point energies, an energy-shift model was employed to develop the accurate optical library for the CST compound for any x value to provide data for future modeling and optimization. The library accuracy was validated through optical simulations of the quantum efficiency of a graded CST solar cell using the finite-difference time-domain method by replicating the Se profile in the absorber layer measured through secondary ion mass spectrometry.
{"title":"Development of an Optical Library for Coevaporated CdSexTe1−x","authors":"António J. N. Oliveira;Bin Du;Kevin D. Dobson;Jennifer P. Teixeira;Maria R. P. Correia;Pedro M. P. Salomé;William N. Shafarman","doi":"10.1109/JPHOTOV.2024.3507079","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3507079","url":null,"abstract":"The conversion efficiency of CdTe solar cells may be improved by bandgap engineering, i.e., changing the bandgap value through the addition of Se in the absorber. The Se alloying enables a short-circuit current density improvement, as it leads to a bandgap energy value decrease. Furthermore, it has been associated with increased minority carrier lifetimes, assuring high open-circuit voltage values. An Se gradient profile control can further optimize the solar cell performance. Thus, an optical model baseline of the CdSe<italic><sub>x</sub></i>Te<sub>1−</sub><italic><sub>x</sub></i> (CST) compound was developed. Spectroscopic ellipsometry measurements were conducted to accurately extract the optical constants of ten CST layers deposited through coevaporation with <italic>x</i> varying from 0 to 1. Using the measured dielectric function spectra from the discrete CST layers with varying <italic>x</i>, and considering the composition-induced shift in the critical point energies, an energy-shift model was employed to develop the accurate optical library for the CST compound for any <italic>x</i> value to provide data for future modeling and optimization. The library accuracy was validated through optical simulations of the quantum efficiency of a graded CST solar cell using the finite-difference time-domain method by replicating the Se profile in the absorber layer measured through secondary ion mass spectrometry.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 2","pages":"252-260"},"PeriodicalIF":2.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-04DOI: 10.1109/JPHOTOV.2024.3501403
Preeti Kumari Sahu;Efstratios I. Batzelis;Chandan Chakraborty;J. N. Roy
Although the bifacial photovoltaic (PV) module is now a mature technology, there still exists a gap in the literature on its electrical modeling and equivalent circuit representation. Most published studies have mainly focused on the photocurrent while overlooking other crucial parameters for the electrical response of the module. Even so, the photocurrent of the bifacial module is simplistically treated as the sum of individual currents of the front and rear sides, a hypothesis challenged in this study. Notably, our research has uncovered a discrepancy that can exceed 15%, and we address this issue by introducing a correction factor in this article. This article introduces a comprehensive electrical model that effectively integrates bifacial PV modules' front and rear sides into a single $-$ circuit representation. This novel model adopts the single $-$ diode equivalent circuit, formulating each of the five parameters as a function of the individual side's parameters. Indoor and outdoor measurements validate the accuracy improvement brought by this model, which can benefit energy yield studies and our theoretical understanding of bifacial PV systems.
{"title":"Electrical Modeling of Bifacial PV Modules","authors":"Preeti Kumari Sahu;Efstratios I. Batzelis;Chandan Chakraborty;J. N. Roy","doi":"10.1109/JPHOTOV.2024.3501403","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3501403","url":null,"abstract":"Although the bifacial photovoltaic (PV) module is now a mature technology, there still exists a gap in the literature on its electrical modeling and equivalent circuit representation. Most published studies have mainly focused on the photocurrent while overlooking other crucial parameters for the electrical response of the module. Even so, the photocurrent of the bifacial module is simplistically treated as the sum of individual currents of the front and rear sides, a hypothesis challenged in this study. Notably, our research has uncovered a discrepancy that can exceed 15%, and we address this issue by introducing a correction factor in this article. This article introduces a comprehensive electrical model that effectively integrates bifacial PV modules' front and rear sides into a single \u0000<inline-formula><tex-math>$-$</tex-math></inline-formula>\u0000 circuit representation. This novel model adopts the single \u0000<inline-formula><tex-math>$-$</tex-math></inline-formula>\u0000 diode equivalent circuit, formulating each of the five parameters as a function of the individual side's parameters. Indoor and outdoor measurements validate the accuracy improvement brought by this model, which can benefit energy yield studies and our theoretical understanding of bifacial PV systems.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 1","pages":"117-125"},"PeriodicalIF":2.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-04DOI: 10.1109/JPHOTOV.2024.3496479
Yosuke Abe;Takahito Nishimura;Akira Yamada
This study focuses on the impact of MoSe 2 at the Mo/Cu(In,Ga)Se 2 (CIGS) interface on back contact characteristics in CIGS solar cells. The unintentionally formed MoSe 2 layer has been reported to establish a quasi-ohmic contact at the Mo/CIGS interface. In this research, we construct a device model for the CIGS solar cells with the MoSe 2 intermediate layer using the solar cell capacitance simulator (SCAPS-1D) considering the experimentally measured physical properties. By assuming Mo vacancies as the source of p-type conductivity of MoSe 2 , we demonstrate the reproducibility of the experimental series resistance. At the Mo/MoSe 2 interface, a Schottky barrier of around 0.9 eV for holes is formed due to the difference in their work functions. It is revealed that the quasi-ohmic contact is formed by recombination between holes and electrons through the defect in the MoSe 2 , despite the Schottky barrier. Since the recombination at the MoSe 2 layer follows the SRH model, the density of Mo vacancy significantly reduces the series resistance. Meanwhile, the decrease in the series resistance by the increase in the Mo vacancy saturates at around 0.83 Ω·cm 2 . To further reduce series resistance, Nb doping into the MoSe 2 is proposed in SCAPS-1D, enhancing p-type conductivity. It is disclosed that the Nb doping induces a transition in dominant hole transport from recombination toward tunneling, resulting in a decrease in the series resistance. If the doping density of the Nb exceeds 5 × 1019 cm −3 , the series resistance becomes comparable to the flat band condition of the back contact.
{"title":"Impact of MoSe2 Layer on Carrier Transport at the Back Contact in Cu(In,Ga)Se2 Solar Cells","authors":"Yosuke Abe;Takahito Nishimura;Akira Yamada","doi":"10.1109/JPHOTOV.2024.3496479","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3496479","url":null,"abstract":"This study focuses on the impact of MoSe\u0000<sub>2</sub>\u0000 at the Mo/Cu(In,Ga)Se\u0000<sub>2</sub>\u0000 (CIGS) interface on back contact characteristics in CIGS solar cells. The unintentionally formed MoSe\u0000<sub>2</sub>\u0000 layer has been reported to establish a quasi-ohmic contact at the Mo/CIGS interface. In this research, we construct a device model for the CIGS solar cells with the MoSe\u0000<sub>2</sub>\u0000 intermediate layer using the solar cell capacitance simulator (SCAPS-1D) considering the experimentally measured physical properties. By assuming Mo vacancies as the source of p-type conductivity of MoSe\u0000<sub>2</sub>\u0000, we demonstrate the reproducibility of the experimental series resistance. At the Mo/MoSe\u0000<sub>2</sub>\u0000 interface, a Schottky barrier of around 0.9 eV for holes is formed due to the difference in their work functions. It is revealed that the quasi-ohmic contact is formed by recombination between holes and electrons through the defect in the MoSe\u0000<sub>2</sub>\u0000, despite the Schottky barrier. Since the recombination at the MoSe\u0000<sub>2</sub>\u0000 layer follows the SRH model, the density of Mo vacancy significantly reduces the series resistance. Meanwhile, the decrease in the series resistance by the increase in the Mo vacancy saturates at around 0.83 Ω·cm\u0000<sup>2</sup>\u0000. To further reduce series resistance, Nb doping into the MoSe\u0000<sub>2</sub>\u0000 is proposed in SCAPS-1D, enhancing p-type conductivity. It is disclosed that the Nb doping induces a transition in dominant hole transport from recombination toward tunneling, resulting in a decrease in the series resistance. If the doping density of the Nb exceeds 5 × 1019 cm\u0000<sup>−3</sup>\u0000, the series resistance becomes comparable to the flat band condition of the back contact.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 1","pages":"79-86"},"PeriodicalIF":2.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10777511","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-02DOI: 10.1109/JPHOTOV.2024.3496484
Theresa E. Saenz;Daniel Curry;AJ Gray;Ryan Muzzio;Jackson W. Schall;Myles A. Steiner
Eliminating photolithography from solar cell processing is a significant opportunity for cost reduction for III–V solar cells. In this work, we explore femtosecond laser ablation as an alternative to contact photolithography and wet chemical etching for mesa isolation. We demonstrate both GaAs and GaInP solar cells mesa-isolated by femtosecond laser ablation with minimal to no loss in solar cell performance. We show the best results with a 400 fs UV pulsed laser and a short clean-up etch that also serves as a contact layer removal etch.
{"title":"Lithography-Free Mesa Isolation of III–V Solar Cells Through Laser Ablation","authors":"Theresa E. Saenz;Daniel Curry;AJ Gray;Ryan Muzzio;Jackson W. Schall;Myles A. Steiner","doi":"10.1109/JPHOTOV.2024.3496484","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3496484","url":null,"abstract":"Eliminating photolithography from solar cell processing is a significant opportunity for cost reduction for III–V solar cells. In this work, we explore femtosecond laser ablation as an alternative to contact photolithography and wet chemical etching for mesa isolation. We demonstrate both GaAs and GaInP solar cells mesa-isolated by femtosecond laser ablation with minimal to no loss in solar cell performance. We show the best results with a 400 fs UV pulsed laser and a short clean-up etch that also serves as a contact layer removal etch.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 1","pages":"110-116"},"PeriodicalIF":2.5,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1109/JPHOTOV.2024.3492281
C. Casu;M. Buffolo;A. Caria;C. De Santi;N. Trivellin;A. Cester;S. Rampino;M. Bronzoni;M. Mazzer;G. Meneghesso;E. Zanoni;M. Meneghini
In this article, we investigate the optically induced degradation of Cu(InGa)Se 2 (CIGS) solar cells subjected to monochromatic laser irradiation. The devices under test are bifacial CIGS solar cells, fabricated on fluorine-doped SnO 2 glass substrates. The electrical properties under dark and illumination conditions were characterized before laser exposure. The analysis of the current–voltage characteristics indicated that defect-assisted carrier transport dominates within the space charge region. Continuous laser exposure at constant optical power caused a decrease in open-circuit voltage ( V oc ). The study of the dark current–voltage curves highlights a change in the saturation current ( IS ) and ideality factor ( n ), whose increment follows a square-root dependence on time. This behavior is attributed to diffusion of Na ions toward the junction. Conversely, the V oc decay (which is correlated with the turn- on voltage decrease in dark I–V curve) is ascribed to a light-induced defect generation that enhances leakage current at the CdS/CIGS interface.
{"title":"Effect of High Monochromatic Radiation on the Electrical Performance of CIGS Solar Cell","authors":"C. Casu;M. Buffolo;A. Caria;C. De Santi;N. Trivellin;A. Cester;S. Rampino;M. Bronzoni;M. Mazzer;G. Meneghesso;E. Zanoni;M. Meneghini","doi":"10.1109/JPHOTOV.2024.3492281","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3492281","url":null,"abstract":"In this article, we investigate the optically induced degradation of Cu(InGa)Se\u0000<sub>2</sub>\u0000 (CIGS) solar cells subjected to monochromatic laser irradiation. The devices under test are bifacial CIGS solar cells, fabricated on fluorine-doped SnO\u0000<sub>2</sub>\u0000 glass substrates. The electrical properties under dark and illumination conditions were characterized before laser exposure. The analysis of the current–voltage characteristics indicated that defect-assisted carrier transport dominates within the space charge region. Continuous laser exposure at constant optical power caused a decrease in open-circuit voltage (\u0000<italic>V</i>\u0000<sub>oc</sub>\u0000). The study of the dark current–voltage curves highlights a change in the saturation current (\u0000<italic>I<sub>S</sub></i>\u0000) and ideality factor (\u0000<italic>n</i>\u0000), whose increment follows a square-root dependence on time. This behavior is attributed to diffusion of Na ions toward the junction. Conversely, the \u0000<italic>V</i>\u0000<sub>oc</sub>\u0000 decay (which is correlated with the turn-\u0000<sc>on</small>\u0000 voltage decrease in dark \u0000<italic>I–V</i>\u0000 curve) is ascribed to a light-induced defect generation that enhances leakage current at the CdS/CIGS interface.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 1","pages":"73-78"},"PeriodicalIF":2.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10770815","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1109/JPHOTOV.2024.3497135
Atanu Purkayastha;Arun Tej Mallajosyula
This work focuses on the design and development of lead-free halide perovskite solar cells (PSCs). Here, 3-D and 2-D/3-D mixed-dimension tin PSCs have been fabricated by adding phenylethylammonium iodide (PEAI) in varying quantities. A maximum power conversion efficiency (PCE $|$MAX ) of 11.03% has been obtained at a PEAI concentration of 15%, with indium tin oxide (ITO) and Ag as the front and rear electrodes, respectively. Addition of PEAI has also improved the stability of the solar cells. Using the measured properties from this device, monofacial and bifacial designs for the same material stack has been simulated by using suitable rear electrodes, without changing the front electrode. Silvaco 2-D TCAD software has been used for this purpose. With Ag and ITO as rear electrodes, the monofacial designs gave PCE $|$ MAX values of 17.94% and 12.79%, respectively. On the other hand, the bifacial design with a concurrent AM1.5G illumination of 1 sun intensity, the device gave a PCE $|$ MAX of 26.55%. The study also examined the impact of albedo effects from various reflecting surfaces on the performance of this bifacial perovskite solar cell (BPSC). Notably, snow albedo positively influenced efficiency of the BPSC, increasing it by 38.85% compared with that of monofacial perovskite solar cell (MPSC) with Ag rear electrode. Conversely, albedos from soil, seawater, and pond water resulted in lower efficiencies, even falling below those of MPSCs with Ag back electrodes. These results indicate that bifacial design has the potential to be an efficient and cost-effective solution for tin-based PSCs.
{"title":"Performance of 2-D/3-D Mixed-Dimension Tin Perovskite Solar Cells and Their Prospects Under Bifacial Configuration","authors":"Atanu Purkayastha;Arun Tej Mallajosyula","doi":"10.1109/JPHOTOV.2024.3497135","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3497135","url":null,"abstract":"This work focuses on the design and development of lead-free halide perovskite solar cells (PSCs). Here, 3-D and 2-D/3-D mixed-dimension tin PSCs have been fabricated by adding phenylethylammonium iodide (PEAI) in varying quantities. A maximum power conversion efficiency (PCE\u0000<sub><inline-formula><tex-math>$|$</tex-math></inline-formula>MAX</sub>\u0000) of 11.03% has been obtained at a PEAI concentration of 15%, with indium tin oxide (ITO) and Ag as the front and rear electrodes, respectively. Addition of PEAI has also improved the stability of the solar cells. Using the measured properties from this device, monofacial and bifacial designs for the same material stack has been simulated by using suitable rear electrodes, without changing the front electrode. Silvaco 2-D TCAD software has been used for this purpose. With Ag and ITO as rear electrodes, the monofacial designs gave PCE\u0000<sub><inline-formula><tex-math>$|$</tex-math></inline-formula> MAX</sub>\u0000 values of 17.94% and 12.79%, respectively. On the other hand, the bifacial design with a concurrent AM1.5G illumination of 1 sun intensity, the device gave a PCE\u0000<sub><inline-formula><tex-math>$|$</tex-math></inline-formula> MAX</sub>\u0000 of 26.55%. The study also examined the impact of albedo effects from various reflecting surfaces on the performance of this bifacial perovskite solar cell (BPSC). Notably, snow albedo positively influenced efficiency of the BPSC, increasing it by 38.85% compared with that of monofacial perovskite solar cell (MPSC) with Ag rear electrode. Conversely, albedos from soil, seawater, and pond water resulted in lower efficiencies, even falling below those of MPSCs with Ag back electrodes. These results indicate that bifacial design has the potential to be an efficient and cost-effective solution for tin-based PSCs.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 1","pages":"54-60"},"PeriodicalIF":2.5,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1109/JPHOTOV.2024.3496475
Yaling Wang;Yi Ding;Liying Yang;Shougen Yin;Sheng Xu;Haina Zhu;Hong Ge
In this work, the SnO 2 -Ti 3 C 2 hybrid electron transport layer (ETL) was prepared by incorporating two-dimensional Ti 3 C 2 -MXene into SnO 2 and appropriate ultraviolet (UV) ozone treatment. The synergistic effect of Ti 3 C 2 introduction and UV ozone treatment on the charge transport capacity of SnO 2 ETL, interface properties of ETL/perovskite, perovskite morphology, and device performance was systematically investigated. The results show that the introduction of Ti 3 C 2 does not affect the morphology and transmittance of SnO 2 ETL. The perovskite films based on SnO 2 -Ti 3 C 2 are not only dense, but also have smaller surface roughness, more uniform, and larger grain size, even penetrating the entire perovskite film. The surface oxidation of Ti 3 C 2 induced by UV-ozone treatment enhanced the charge transport capacity of ETL. The electron extraction and charge transfer at the interface between SnO 2 -Ti 3 C 2 ETL and perovskite are higher, and carrier recombination is effectively suppressed. Perovskite solar cells (PSCs) based on SnO 2 -Ti 3 C 2 ETL have larger charge recombination impedance and higher electron mobility, mainly due to enhanced ETL charge transport and optimization of interface properties. The short-circuit current ( J sc) and filling factor (FF) of PSCs are increased by 5% and 7% respectively, delivering a champion device with a relatively high FF of 79.38% and high power conversion efficiency of 19.52%, as well as good stability. Thus, this study provides a simple and effective method for the preparation of efficient and repeatable PSCs and paves the way for the industrialization of PSCs to a certain extent.
{"title":"SnO2-Ti3C2 Blends as Electron Transport Layer for Efficient and Easily Fabricated Planar Perovskite Solar Cells","authors":"Yaling Wang;Yi Ding;Liying Yang;Shougen Yin;Sheng Xu;Haina Zhu;Hong Ge","doi":"10.1109/JPHOTOV.2024.3496475","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3496475","url":null,"abstract":"In this work, the SnO\u0000<sub>2</sub>\u0000-Ti\u0000<sub>3</sub>\u0000C\u0000<sub>2</sub>\u0000 hybrid electron transport layer (ETL) was prepared by incorporating two-dimensional Ti\u0000<sub>3</sub>\u0000C\u0000<sub>2</sub>\u0000-MXene into SnO\u0000<sub>2</sub>\u0000 and appropriate ultraviolet (UV) ozone treatment. The synergistic effect of Ti\u0000<sub>3</sub>\u0000C\u0000<sub>2</sub>\u0000 introduction and UV ozone treatment on the charge transport capacity of SnO\u0000<sub>2</sub>\u0000 ETL, interface properties of ETL/perovskite, perovskite morphology, and device performance was systematically investigated. The results show that the introduction of Ti\u0000<sub>3</sub>\u0000C\u0000<sub>2</sub>\u0000 does not affect the morphology and transmittance of SnO\u0000<sub>2</sub>\u0000 ETL. The perovskite films based on SnO\u0000<sub>2</sub>\u0000-Ti\u0000<sub>3</sub>\u0000C\u0000<sub>2</sub>\u0000 are not only dense, but also have smaller surface roughness, more uniform, and larger grain size, even penetrating the entire perovskite film. The surface oxidation of Ti\u0000<sub>3</sub>\u0000C\u0000<sub>2</sub>\u0000 induced by UV-ozone treatment enhanced the charge transport capacity of ETL. The electron extraction and charge transfer at the interface between SnO\u0000<sub>2</sub>\u0000-Ti\u0000<sub>3</sub>\u0000C\u0000<sub>2</sub>\u0000 ETL and perovskite are higher, and carrier recombination is effectively suppressed. Perovskite solar cells (PSCs) based on SnO\u0000<sub>2</sub>\u0000-Ti\u0000<sub>3</sub>\u0000C\u0000<sub>2</sub>\u0000 ETL have larger charge recombination impedance and higher electron mobility, mainly due to enhanced ETL charge transport and optimization of interface properties. The short-circuit current (\u0000<italic>J</i>\u0000sc) and filling factor (FF) of PSCs are increased by 5% and 7% respectively, delivering a champion device with a relatively high FF of 79.38% and high power conversion efficiency of 19.52%, as well as good stability. Thus, this study provides a simple and effective method for the preparation of efficient and repeatable PSCs and paves the way for the industrialization of PSCs to a certain extent.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 1","pages":"61-66"},"PeriodicalIF":2.5,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1109/JPHOTOV.2024.3496520
Mykhaylo Evstigneev
Analytical expressions for photon reabsorption probability in a solar cell, in which one of the surfaces, front or back, is specular and the other one is diffusive are obtained within the ray optics approximation. Due to the free carrier absorption, the light-generated current and the radiative recombination coefficient depend on the electron-hole pair density within the cell. Accurate analytical approximations that describe this effect are derived. These formulae are applied to evaluate the limit efficiency of a c-Si solar cells, whose one surface is specular and the other is diffusive, under AM1.5G irradiation at $ 25,^{circ }$ C. For the solar cells with specular front and diffusive back surfaces, the efficiency is maximized at the cell thickness of 110 $mu$ m and has a value of 29.4%. In the configuration with diffusive front surface, the limiting efficiency of 29.5% is achieved at the optimal thickness of 100 $mu$ m regardless of the texturing type of the back surface.
{"title":"Photon Recycling and Efficiency Limit of a Silicon Solar Cell With a Specular and a Diffusive Surface","authors":"Mykhaylo Evstigneev","doi":"10.1109/JPHOTOV.2024.3496520","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3496520","url":null,"abstract":"Analytical expressions for photon reabsorption probability in a solar cell, in which one of the surfaces, front or back, is specular and the other one is diffusive are obtained within the ray optics approximation. Due to the free carrier absorption, the light-generated current and the radiative recombination coefficient depend on the electron-hole pair density within the cell. Accurate analytical approximations that describe this effect are derived. These formulae are applied to evaluate the limit efficiency of a c-Si solar cells, whose one surface is specular and the other is diffusive, under AM1.5G irradiation at \u0000<inline-formula><tex-math>$ 25,^{circ }$</tex-math></inline-formula>\u0000C. For the solar cells with specular front and diffusive back surfaces, the efficiency is maximized at the cell thickness of 110 \u0000<inline-formula><tex-math>$mu$</tex-math></inline-formula>\u0000m and has a value of 29.4%. In the configuration with diffusive front surface, the limiting efficiency of 29.5% is achieved at the optimal thickness of 100 \u0000<inline-formula><tex-math>$mu$</tex-math></inline-formula>\u0000m regardless of the texturing type of the back surface.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 1","pages":"95-104"},"PeriodicalIF":2.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A high-efficiency indium gallium nitride (InGaN) laser photovoltaic cell (LPVC) was demonstrated to achieve a photoelectric conversion efficiency (η) of 23.09% by incorporating an AlGaN strain compensation layer (SCL) grown on a (0001)-oriented patterned sapphire substrate (PSS). The photoluminescence spectra confirm that the peak splitting is reduced after the insertion of AlGaN SCL, indicating a more uniform distribution of In. In addition, the full width at half maximum of the sample is narrowed, indicating that the crystal quality is improved after the insertion of AlGaN SCL. The X-ray diffraction analysis reveals the effective modulation of strain relaxation in InGaN materials by the AlGaN SCL, enhancing steepness of the interface between the well and the barrier in the active region compared with materials without the AlGaN SCL. Furthermore, Raman analysis shows an additional release of GaN compressive stress in InGaN materials, providing full validation for the stress regulation model from introducing the AlGaN SCL. Finally, introducing material parameters into Silvaco software resulted in simulation and experimental errors of less than 2%, the critical role of SCL in efficiency improvement is validated. Valuable insights on optimizing device design for high-efficiency InGaN LPVCs are provided.
{"title":"Performance Enhancement of InGaN Laser Photovoltaic Cell With AlGaN Strain Compensation Layer Irradiated by 450 nm Laser","authors":"Heng-Sheng Shan;Yi-Xin Wang;Cheng-Ke Li;Ning Wang;Xiao-Ya Li;Shu-Fang Ma;Bing-She Xu","doi":"10.1109/JPHOTOV.2024.3495024","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3495024","url":null,"abstract":"A high-efficiency indium gallium nitride (InGaN) laser photovoltaic cell (LPVC) was demonstrated to achieve a photoelectric conversion efficiency (η) of 23.09% by incorporating an AlGaN strain compensation layer (SCL) grown on a (0001)-oriented patterned sapphire substrate (PSS). The photoluminescence spectra confirm that the peak splitting is reduced after the insertion of AlGaN SCL, indicating a more uniform distribution of In. In addition, the full width at half maximum of the sample is narrowed, indicating that the crystal quality is improved after the insertion of AlGaN SCL. The X-ray diffraction analysis reveals the effective modulation of strain relaxation in InGaN materials by the AlGaN SCL, enhancing steepness of the interface between the well and the barrier in the active region compared with materials without the AlGaN SCL. Furthermore, Raman analysis shows an additional release of GaN compressive stress in InGaN materials, providing full validation for the stress regulation model from introducing the AlGaN SCL. Finally, introducing material parameters into Silvaco software resulted in simulation and experimental errors of less than 2%, the critical role of SCL in efficiency improvement is validated. Valuable insights on optimizing device design for high-efficiency InGaN LPVCs are provided.","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"15 1","pages":"105-109"},"PeriodicalIF":2.5,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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