Thierry de Vrijer, Maik Wiering, David A. van Nijen, G. Padmakumar, Sriram Sambamurthy, G. Limodio, A. Smets
Surface textures that result in high optical yields are crucial for high efficiency photovoltaic (PV) devices. In this work three different texturing approaches are presented that result in smooth concave structures devoid of sharp features. Such features can sustain the crack-free growth of device quality nano- to poly-crystalline materials such as nano-crystalline silicon, perovskites or C(I)GS, facilitating routes towards hybrid multijunction PV devices. A sacrificial implanted poly-c-Si layer is used to develop a random surface texture for the first texturing approach (Tsac). The influence of the processing conditions, such as layer thickness, implantation energy, dose and ion type, annealing time and temperature, of the sacrificial layer on the developed surface features is investigated. Additionally, a photolithographically developed honeycomb texture (Thoney) is presented. The influence of mask design on the honeycomb features is discussed and a relation is established between the honeycomb period and crack formation in nano-crystalline silicon layers. The reflective properties (spectral reflection, haze in reflection and angular intensity distribution) of these approaches are characterized and compared to a third texturing approach, Tsp, the result of chemically smoothened pyramidal <111> features. It was demonstrated that high optical scattering yields can be achieved for both Thoney and Tsp. Additionally, the performance of a-Si/nc-Si tandem devices processed onto the different textures is compared using both optical device simulations and real device measurements. Simulations demonstrate strong improvements in Jsc-sum (≈45%), in reference to a flat surface, and high Voc*FF of over 1 V are demonstrated for Tsp.
{"title":"The optical performance of random and periodic textured mono crystalline silicon surfaces for photovoltaic applications","authors":"Thierry de Vrijer, Maik Wiering, David A. van Nijen, G. Padmakumar, Sriram Sambamurthy, G. Limodio, A. Smets","doi":"10.1051/epjpv/2022021","DOIUrl":"https://doi.org/10.1051/epjpv/2022021","url":null,"abstract":"Surface textures that result in high optical yields are crucial for high efficiency photovoltaic (PV) devices. In this work three different texturing approaches are presented that result in smooth concave structures devoid of sharp features. Such features can sustain the crack-free growth of device quality nano- to poly-crystalline materials such as nano-crystalline silicon, perovskites or C(I)GS, facilitating routes towards hybrid multijunction PV devices. A sacrificial implanted poly-c-Si layer is used to develop a random surface texture for the first texturing approach (Tsac). The influence of the processing conditions, such as layer thickness, implantation energy, dose and ion type, annealing time and temperature, of the sacrificial layer on the developed surface features is investigated. Additionally, a photolithographically developed honeycomb texture (Thoney) is presented. The influence of mask design on the honeycomb features is discussed and a relation is established between the honeycomb period and crack formation in nano-crystalline silicon layers. The reflective properties (spectral reflection, haze in reflection and angular intensity distribution) of these approaches are characterized and compared to a third texturing approach, Tsp, the result of chemically smoothened pyramidal <111> features. It was demonstrated that high optical scattering yields can be achieved for both Thoney and Tsp. Additionally, the performance of a-Si/nc-Si tandem devices processed onto the different textures is compared using both optical device simulations and real device measurements. Simulations demonstrate strong improvements in Jsc-sum (≈45%), in reference to a flat surface, and high Voc*FF of over 1 V are demonstrated for Tsp.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57828411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The construction of a small-sized panel based on anthocyanins from Erythrina crista-galli as sensitizers is reported in this work. The device, named KD12, was placed indoors at the Artigas Antarctic Scientific Base from March 2019 to December 2020. Here is released for the first time, the indoor installation of dye-sensitized solar cells based on pigments from the Uruguayan national flower at an Antarctic Base and the evaluation of their performance during nineteen months. The panel showed good stability and maintained its efficiency conversion performance over the period. The output power, voltage and conversion efficiency generated for this device mainly depended on irradiance and external factors as light reflection due to snow or artificial bulbs near the area. Additional protection was provided by the double-glass window in front of the panel, lowering lighting irradiance and changing spectral characteristics of the light incident the device. A new prospect raised here: the potential application of anthocyanins as sensitizers for indoor electricity generation in the Antarctic area with long term operability, where low temperatures are helpful considering the thermal stability of the dyes. These constitute an interesting first step of a low-cost alternative searching for clean energy generation sources, focusing on a cold region like Antarctica.
{"title":"A small-sized DSSC panel based on the Uruguayan national flower dye tested at the Antarctic Artigas Base","authors":"M. F. Cerdá","doi":"10.1051/epjpv/2021015","DOIUrl":"https://doi.org/10.1051/epjpv/2021015","url":null,"abstract":"The construction of a small-sized panel based on anthocyanins from Erythrina crista-galli as sensitizers is reported in this work. The device, named KD12, was placed indoors at the Artigas Antarctic Scientific Base from March 2019 to December 2020. Here is released for the first time, the indoor installation of dye-sensitized solar cells based on pigments from the Uruguayan national flower at an Antarctic Base and the evaluation of their performance during nineteen months. The panel showed good stability and maintained its efficiency conversion performance over the period. The output power, voltage and conversion efficiency generated for this device mainly depended on irradiance and external factors as light reflection due to snow or artificial bulbs near the area. Additional protection was provided by the double-glass window in front of the panel, lowering lighting irradiance and changing spectral characteristics of the light incident the device. A new prospect raised here: the potential application of anthocyanins as sensitizers for indoor electricity generation in the Antarctic area with long term operability, where low temperatures are helpful considering the thermal stability of the dyes. These constitute an interesting first step of a low-cost alternative searching for clean energy generation sources, focusing on a cold region like Antarctica.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Tamin, D. Chaumont, O. Heintz, A. Leray, M. Adnane
This paper investigates the effects of partial substitution of zinc (Zn) in pure sulfide kesterite (Cu2ZnSnS4) by cadmium (Cd) and manganese (Mn) incorporation. Thin films of Cu2ZnSnS4 (CZTS), Cu2Zn1–xCdxSnS4 (CCZTS) and Cu2Zn1–xMnxSnS4(CMZTS) were produced chemically. A comparison of pure CZTS with CCZTS and CMZTS was performed to study the influence of Cd and Mn incorporation on the morphology, structure, optical and electronic properties of the films. The results show an improvement of the morphology and an adjustment of the band gap and valence band position by partial substitution of Zn with Cd and Mn. In addition, for the first time, the band alignment at the absorber/buffer hetero-interface is studied with partial Zn substitution. Band alignments at the absorber/buffer hetero-interface were estimated by XPS and UV/Visible measurements. The results show a cliff-like CBO for CZTS/CdS heterojunction, a spike-like CBO for CCZTS/CdS and a near flat-band CBO for CMZTS/CdS heterojunction.
{"title":"Improvement of hetero-interface engineering by partial substitution of Zn in Cu2ZnSnS4-based solar cells","authors":"C. Tamin, D. Chaumont, O. Heintz, A. Leray, M. Adnane","doi":"10.1051/epjpv/2022022","DOIUrl":"https://doi.org/10.1051/epjpv/2022022","url":null,"abstract":"This paper investigates the effects of partial substitution of zinc (Zn) in pure sulfide kesterite (Cu2ZnSnS4) by cadmium (Cd) and manganese (Mn) incorporation. Thin films of Cu2ZnSnS4 (CZTS), Cu2Zn1–xCdxSnS4 (CCZTS) and Cu2Zn1–xMnxSnS4(CMZTS) were produced chemically. A comparison of pure CZTS with CCZTS and CMZTS was performed to study the influence of Cd and Mn incorporation on the morphology, structure, optical and electronic properties of the films. The results show an improvement of the morphology and an adjustment of the band gap and valence band position by partial substitution of Zn with Cd and Mn. In addition, for the first time, the band alignment at the absorber/buffer hetero-interface is studied with partial Zn substitution. Band alignments at the absorber/buffer hetero-interface were estimated by XPS and UV/Visible measurements. The results show a cliff-like CBO for CZTS/CdS heterojunction, a spike-like CBO for CCZTS/CdS and a near flat-band CBO for CMZTS/CdS heterojunction.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Govaerts, Bin Luo, T. Borgers, Rik Van Dyck, A. van der Heide, L. Tous, Arnaud Morlier, F. Lisco, L. Cerasti, M. Galiazzo, J. Poortmans
In this paper we report on our approach on integrating c-Si PV into lightweight structures, in particular towards vehicle integration. To this end we want to get rid of the (bulk weight of the) glass but seek a suitable replacement in terms of mechanical stability. First we elaborate on the most basic standards and norms that VIPV products should relate to in terms of (thermo-)mechanical testing. Then, for the experimental part, 2 concepts are investigated. In a first approach, we reinforced the encapsulant with glass fibre material, while in a second one we applied a dedicated glass-fibre-reinforced sheet as a replacement of the backsheet. In both cases we stay as close as possible to using commercially available material. For each approach we elaborate the testing that has been carried out: thermal cycling, vibrations, mechanical shock and hail impact. On a final note, we point out some initial damp heat testing results, that are a particular challenge for light-weight modules without glass.
{"title":"Development and testing of light-weight PV modules based on glass-fibre reinforcement","authors":"J. Govaerts, Bin Luo, T. Borgers, Rik Van Dyck, A. van der Heide, L. Tous, Arnaud Morlier, F. Lisco, L. Cerasti, M. Galiazzo, J. Poortmans","doi":"10.1051/epjpv/2022007","DOIUrl":"https://doi.org/10.1051/epjpv/2022007","url":null,"abstract":"In this paper we report on our approach on integrating c-Si PV into lightweight structures, in particular towards vehicle integration. To this end we want to get rid of the (bulk weight of the) glass but seek a suitable replacement in terms of mechanical stability. First we elaborate on the most basic standards and norms that VIPV products should relate to in terms of (thermo-)mechanical testing. Then, for the experimental part, 2 concepts are investigated. In a first approach, we reinforced the encapsulant with glass fibre material, while in a second one we applied a dedicated glass-fibre-reinforced sheet as a replacement of the backsheet. In both cases we stay as close as possible to using commercially available material. For each approach we elaborate the testing that has been carried out: thermal cycling, vibrations, mechanical shock and hail impact. On a final note, we point out some initial damp heat testing results, that are a particular challenge for light-weight modules without glass.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57828202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Barreau, E. Bertin, A. Crossay, O. Durand, L. Arzel, S. Harel, T. Lepetit, L. Assmann, E. Gautron, D. Lincot
The interest for pure sulfide Cu(In,Ga)S2 chalcopyrite thin films is increasing again because their optical properties make them relevant candidates to be applied as top cell absorbers in tandem structures. Nonetheless, their use as so is still hindered by the level of single-junction cells performance achieved so far, which are far below those demonstrated by selenide absorbers. Amongst the reasons at the origin of the limited efficiency of Cu(In,Ga)S2-based solar devices, one can mention the poor tolerance of S-chalcopyrite to Cu deficiency. In fact, Cu-poor Cu(In,Ga)S2 films contain CuIn5S8 thiospinel secondary phase which is harmful for device performance. In the present work, we investigate Cu(In,Ga)S2 thin films grown by a modified three-stage process making use of graded indium and gallium fluxes during the first stage. The resulting absorbers are single phase and made of large grains extended throughout the entire film thickness. We propose that such a morphology is a proof of the recrystallization of the entire film during the synthesis. Devices prepared from those films and buffered with bath deposited CdS demonstrate outstanding efficiency of 16.0%. Replacing CdS by Zn(O,S) buffer layer leads to increased open circuit voltage and short circuit current; however, performance become limited by lowered fill factor.
{"title":"Investigation of co-evaporated polycrystalline Cu(In,Ga)S2 thin film yielding 16.0 % efficiency solar cell","authors":"N. Barreau, E. Bertin, A. Crossay, O. Durand, L. Arzel, S. Harel, T. Lepetit, L. Assmann, E. Gautron, D. Lincot","doi":"10.1051/epjpv/2022014","DOIUrl":"https://doi.org/10.1051/epjpv/2022014","url":null,"abstract":"The interest for pure sulfide Cu(In,Ga)S2 chalcopyrite thin films is increasing again because their optical properties make them relevant candidates to be applied as top cell absorbers in tandem structures. Nonetheless, their use as so is still hindered by the level of single-junction cells performance achieved so far, which are far below those demonstrated by selenide absorbers. Amongst the reasons at the origin of the limited efficiency of Cu(In,Ga)S2-based solar devices, one can mention the poor tolerance of S-chalcopyrite to Cu deficiency. In fact, Cu-poor Cu(In,Ga)S2 films contain CuIn5S8 thiospinel secondary phase which is harmful for device performance. In the present work, we investigate Cu(In,Ga)S2 thin films grown by a modified three-stage process making use of graded indium and gallium fluxes during the first stage. The resulting absorbers are single phase and made of large grains extended throughout the entire film thickness. We propose that such a morphology is a proof of the recrystallization of the entire film during the synthesis. Devices prepared from those films and buffered with bath deposited CdS demonstrate outstanding efficiency of 16.0%. Replacing CdS by Zn(O,S) buffer layer leads to increased open circuit voltage and short circuit current; however, performance become limited by lowered fill factor.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57828292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Kanevce, S. Essig, S. Paetel, W. Hempel, D. Hariskos, Theresa Magorian Friedlmeier
Partial substitution of Cu by Ag in Cu(In,Ga)Se2 (CIGS) solar cells is advantageous as it allows lower temperature growth while maintaining high performance. To understand the role of Ag on device performance, we present a comprehensive analysis of (Ag,Cu)(In,Ga)Se2 (ACIGS) samples with an [Ag]/([Ag]+[Cu]) (AAC) ratio varying from 7% to 22%. The analysis involves a set of material and device characterization techniques as well as numerical simulations. Multiple electrical and material properties show a systematic dependence on the increased Ag content. These include a carrier-density decrease, a grain-size increase, and a flattened [Ga]/([Ga] + [In]) (GGI) profile leading to a higher minimum band gap energy and a reduced back grading. Although the best performing device (PCE = 18.0%) in this set has an AAC = 7%, cells with higher Ag contents have an advantage of a smoother absorber surface which is attractive for tandem applications, despite their slightly inferior conversion efficiencies (PCE = 16.4% for 22% Ag).
{"title":"Impact of Ag content on device properties of Cu(In,Ga)Se2 solar cells","authors":"A. Kanevce, S. Essig, S. Paetel, W. Hempel, D. Hariskos, Theresa Magorian Friedlmeier","doi":"10.1051/epjpv/2022026","DOIUrl":"https://doi.org/10.1051/epjpv/2022026","url":null,"abstract":"Partial substitution of Cu by Ag in Cu(In,Ga)Se2 (CIGS) solar cells is advantageous as it allows lower temperature growth while maintaining high performance. To understand the role of Ag on device performance, we present a comprehensive analysis of (Ag,Cu)(In,Ga)Se2 (ACIGS) samples with an [Ag]/([Ag]+[Cu]) (AAC) ratio varying from 7% to 22%. The analysis involves a set of material and device characterization techniques as well as numerical simulations. Multiple electrical and material properties show a systematic dependence on the increased Ag content. These include a carrier-density decrease, a grain-size increase, and a flattened [Ga]/([Ga] + [In]) (GGI) profile leading to a higher minimum band gap energy and a reduced back grading. Although the best performing device (PCE = 18.0%) in this set has an AAC = 7%, cells with higher Ag contents have an advantage of a smoother absorber surface which is attractive for tandem applications, despite their slightly inferior conversion efficiencies (PCE = 16.4% for 22% Ag).","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57828099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The tracking of the maximum power point (MPP) of a photovoltaic (PV) solar panel is an important part of a PV generation chain. In order to track maximum power from the solar arrays, it is necessary to control the output impedance of the PV panel, so that the circuit can be operated at its Maximum Power Point (MPP), despite the unavoidable changes in the climate conditions such as temperature and Irradiance. A new MPPT analog technique to track the Maximum Power Point (MPP) of PV arrays is proposed. This new technique uses simple and classical functions of electronic circuits. An Off-Grid PV system was considered to apply and validate the proposed new technique. The entire circuit was implemented in circuit-oriented simulator Proteus-ISIS. We present the results associated with the design, the realization, and the experimentation of a PV system equipped with a new analog MPPT command. The obtained results have shown good efficiency of analog technique (more than 98.5%). The second part of the paper consists of the description of the design and the realization of the novel analog MPPT integrated chip. The integrated circuit (IC) was designed and realized using HV CMOS technology 0.35-µm.
{"title":"Design and realization of an analog integrated circuit for maximum power point tracking of photovoltaic panels","authors":"Abdulrahman Alahdal, A. Ammous, K. Ammous","doi":"10.1051/epjpv/2022002","DOIUrl":"https://doi.org/10.1051/epjpv/2022002","url":null,"abstract":"The tracking of the maximum power point (MPP) of a photovoltaic (PV) solar panel is an important part of a PV generation chain. In order to track maximum power from the solar arrays, it is necessary to control the output impedance of the PV panel, so that the circuit can be operated at its Maximum Power Point (MPP), despite the unavoidable changes in the climate conditions such as temperature and Irradiance. A new MPPT analog technique to track the Maximum Power Point (MPP) of PV arrays is proposed. This new technique uses simple and classical functions of electronic circuits. An Off-Grid PV system was considered to apply and validate the proposed new technique. The entire circuit was implemented in circuit-oriented simulator Proteus-ISIS. We present the results associated with the design, the realization, and the experimentation of a PV system equipped with a new analog MPPT command. The obtained results have shown good efficiency of analog technique (more than 98.5%). The second part of the paper consists of the description of the design and the realization of the novel analog MPPT integrated chip. The integrated circuit (IC) was designed and realized using HV CMOS technology 0.35-µm.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mame Cheikh Diouf, Mactar Faye, Ababacar Thiam, V. Sambou
The performance of large-scale PV solar plant installed in sub-Saharan regions is affected by the deposition of dust on the surface of the PV modules. Frequent cleaning of the PV modules increases the profitability of PV solar plants. The objective of this study is to determine the optimal cleaning cycle of a PV solar plant subjected to a wind loaded with sand and dust. This study took place in a PV solar plant installed in Senegal. The measurement data are analysed for a period of two years and used to extract soiling rate. Optimization was done based on the total cost caused by dust on the PV solar plant to minimize the number of days between cleaning events. The results showed that the soiling rate between June and May is 0.34%/day, while a rate of 0.33%/day was recorded in October. The highest soiling rates of 0.42%/day and 0.49%/day were recorded in December and between February and March, respectively. The optimal cleaning cycle for the PV solar plant is 14 days. The total cost of cleaning is reduced by 31% using this optimal cleaning cycle proposed.
{"title":"A framework of optimum cleaning schedule and its financial impact in a large-scale PV solar plant: a case study in Senegal","authors":"Mame Cheikh Diouf, Mactar Faye, Ababacar Thiam, V. Sambou","doi":"10.1051/epjpv/2022019","DOIUrl":"https://doi.org/10.1051/epjpv/2022019","url":null,"abstract":"The performance of large-scale PV solar plant installed in sub-Saharan regions is affected by the deposition of dust on the surface of the PV modules. Frequent cleaning of the PV modules increases the profitability of PV solar plants. The objective of this study is to determine the optimal cleaning cycle of a PV solar plant subjected to a wind loaded with sand and dust. This study took place in a PV solar plant installed in Senegal. The measurement data are analysed for a period of two years and used to extract soiling rate. Optimization was done based on the total cost caused by dust on the PV solar plant to minimize the number of days between cleaning events. The results showed that the soiling rate between June and May is 0.34%/day, while a rate of 0.33%/day was recorded in October. The highest soiling rates of 0.42%/day and 0.49%/day were recorded in December and between February and March, respectively. The optimal cleaning cycle for the PV solar plant is 14 days. The total cost of cleaning is reduced by 31% using this optimal cleaning cycle proposed.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57828389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Charles Seron, T. Desrues, F. Jay, A. Lanterne, F. Torregrosa, G. Borvon, Q. Rafhay, A. Kaminski, S. Dubois
This work presents the development and the application of innovative and sustainable transparent conductive oxide (TCO) materials for contacting polysilicon (poly-Si) on oxide (SiOx) stacks used as passivating contacts in solar cell devices. Adding hydrogen into ZnO:Al (AZO) layers deposited by magnetron sputtering potentially leads to a twofold positive effect. First, it brings hydrogen atoms into the layers, which can enhance both electrical and optical material properties of the TCO. Second, hydrogen can significantly improve cell performances, by fixing dangling bonds at the SiOx/substrate interface and by passivating bulk defects. In situ and ex situ hydrogenation processes have been compared on those multiple aspects with investigation about anneals at 350 °C. AZO layers have been successfully integrated on the front side of complete solar cells featuring poly-Si/SiOx-based passivating contacts, leading to a record conversion efficiency of 22.4% for a cell with AZO. The results show that using AZO instead of an indium based TCO is suitable for passivated contacts solar cell with high temperature route. Thus, it increases the credibility towards large-scale deployments of TCO-based high efficiency silicon solar cells in terms of cost and resources.
{"title":"Hydrogenation of sputtered ZnO:Al layers for double side poly-Si/SiOx solar cells","authors":"Charles Seron, T. Desrues, F. Jay, A. Lanterne, F. Torregrosa, G. Borvon, Q. Rafhay, A. Kaminski, S. Dubois","doi":"10.1051/epjpv/2022005","DOIUrl":"https://doi.org/10.1051/epjpv/2022005","url":null,"abstract":"This work presents the development and the application of innovative and sustainable transparent conductive oxide (TCO) materials for contacting polysilicon (poly-Si) on oxide (SiOx) stacks used as passivating contacts in solar cell devices. Adding hydrogen into ZnO:Al (AZO) layers deposited by magnetron sputtering potentially leads to a twofold positive effect. First, it brings hydrogen atoms into the layers, which can enhance both electrical and optical material properties of the TCO. Second, hydrogen can significantly improve cell performances, by fixing dangling bonds at the SiOx/substrate interface and by passivating bulk defects. In situ and ex situ hydrogenation processes have been compared on those multiple aspects with investigation about anneals at 350 °C. AZO layers have been successfully integrated on the front side of complete solar cells featuring poly-Si/SiOx-based passivating contacts, leading to a record conversion efficiency of 22.4% for a cell with AZO. The results show that using AZO instead of an indium based TCO is suitable for passivated contacts solar cell with high temperature route. Thus, it increases the credibility towards large-scale deployments of TCO-based high efficiency silicon solar cells in terms of cost and resources.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The characteristics of solar cells in the reverse voltage direction are essential for the resilience of a photovoltaic module against partial-shading induced damage. Therefore, it is important to establish a thorough understanding of the mechanisms that lead to reverse breakdown in solar cells. This work studies thin-film solar cells based on Cu(In,Ga)Se2 (CIGS) absorber layers. Systematic material variations are investigated in order to learn more about the mechanisms governing reverse breakdown in these devices. To this end, devices with different thicknesses of the CdS buffer layer and with and without a RbF-post-deposition treatment (PDT) of the absorber layer were fabricated. The resulting current-voltage characteristics at negative voltage biases reveal that devices break down at much more negative voltages if they underwent a PDT, if the buffer layer thickness is increased, or if the buffer layer is not photoexcited. This implies that possibly a PDT may be disadvantageous for the shading tolerance of a module. The further analysis indicates that several mechanisms are involved in the reverse breakdown. Whereas tunneling currents in the buffer layer seem to play a major role for the actual breakdown, the strong effect of the PDT is probably caused by a reduction of shunt leakage currents along grain boundaries which lowers material heating.
{"title":"Exploring reverse-bias characteristics of CIGS solar cells: impact of alkali-post-deposition treatment and CdS buffer layer","authors":"Janet Neerken, R. Schäffler, S. Heise","doi":"10.1051/epjpv/2022023","DOIUrl":"https://doi.org/10.1051/epjpv/2022023","url":null,"abstract":"The characteristics of solar cells in the reverse voltage direction are essential for the resilience of a photovoltaic module against partial-shading induced damage. Therefore, it is important to establish a thorough understanding of the mechanisms that lead to reverse breakdown in solar cells. This work studies thin-film solar cells based on Cu(In,Ga)Se2 (CIGS) absorber layers. Systematic material variations are investigated in order to learn more about the mechanisms governing reverse breakdown in these devices. To this end, devices with different thicknesses of the CdS buffer layer and with and without a RbF-post-deposition treatment (PDT) of the absorber layer were fabricated. The resulting current-voltage characteristics at negative voltage biases reveal that devices break down at much more negative voltages if they underwent a PDT, if the buffer layer thickness is increased, or if the buffer layer is not photoexcited. This implies that possibly a PDT may be disadvantageous for the shading tolerance of a module. The further analysis indicates that several mechanisms are involved in the reverse breakdown. Whereas tunneling currents in the buffer layer seem to play a major role for the actual breakdown, the strong effect of the PDT is probably caused by a reduction of shunt leakage currents along grain boundaries which lowers material heating.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}