Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6745146
James E. Moore, C. Hages, Nathaniel J. Carter, R. Agrawal, Mark S. Lundstrom
IV measurements of thin film solar cells often show a crossover between the illuminated and dark curves. Crossover can occur for several different reasons. In this paper, we explore crossover in CZTSSe solar cells fabricated using nanocrystalline ink deposition with selenization and compare it to crossover in ink-based CIGSSe solar cells. Crossover in CIGSSe appears to be related to traps, as is commonly observed, but crossover in CZTSSe appears to be due to a different mechanism. Using numerical simulation, we show that crossover can arise from a simple explanation that is common to solar cells with different structures and closely related to the built-in potential of the device. Using IVT and CV measurements, we show that both simulations and experimental analysis point to a cross-over voltage in our CZTSSe cells that is directly related to the built-in voltage of the device, and which may play a role in limiting the open-circuit voltage.
{"title":"The physics of Vbi-related IV crossover in thin film solar cells: Applications to ink deposited CZTSSe","authors":"James E. Moore, C. Hages, Nathaniel J. Carter, R. Agrawal, Mark S. Lundstrom","doi":"10.1109/PVSC.2013.6745146","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6745146","url":null,"abstract":"IV measurements of thin film solar cells often show a crossover between the illuminated and dark curves. Crossover can occur for several different reasons. In this paper, we explore crossover in CZTSSe solar cells fabricated using nanocrystalline ink deposition with selenization and compare it to crossover in ink-based CIGSSe solar cells. Crossover in CIGSSe appears to be related to traps, as is commonly observed, but crossover in CZTSSe appears to be due to a different mechanism. Using numerical simulation, we show that crossover can arise from a simple explanation that is common to solar cells with different structures and closely related to the built-in potential of the device. Using IVT and CV measurements, we show that both simulations and experimental analysis point to a cross-over voltage in our CZTSSe cells that is directly related to the built-in voltage of the device, and which may play a role in limiting the open-circuit voltage.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74577346","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744205
C. Álvarez-Macías, B. Monroy, L. Huerta, M. A. Canseco-Martinez, M. Picquart, M. Sanchez, G. Santana
In this work we show the different trends in the optoelectronic properties of polymorphous silicon thin films under light-soaking for long exposure times. These thin films were grown by Plasma Enhanced Chemical Vapor Deposition using dichlorosilane as precursor gas and different hydrogen dilutions. When the samples were illuminated by white light at power density of 100 mW/cm2 (AM1.5 condition) during 250 h continuously, singular behaviors on the photoconductivity measurements were shown. The different trends are explained as a function of the crystalline fraction and chemical composition of these films. XPS shows that an oxidation process takes place throughout the film in some samples grown at high hydrogen dilutions, while other samples grown at low hydrogen dilution show only surface oxidation after ambient exposure. In the same way, XPS spectra show different silicon oxidation states and chlorine presence along of the films. On the other hand, FTIR spectra evidence the absence of mono-and dihydride Si-H bonds around 2000-2150 cm-1. These bonds are generally responsible for the degradation process in amorphous silicon thin films solar cells. With the control of the crystalline fractions and chemical composition, it is possible to avoid the degradation process in thin films silicon solar cells. The role of chlorine and hydrogen related bonds, which can be associated with the level of stability of the films, were inferred from XPS and FTIR analysis. Conductivity and photoconductivity changes on polymorphous silicon thin films were observed when the films are subjected to light-soaking for 15000 minutes. These changes are dependent on the chemical and structural properties of the films.
{"title":"Influence of light-soaking treatment on the optoelectronic properties of polymorphous silicon thin films to be used in solar cells","authors":"C. Álvarez-Macías, B. Monroy, L. Huerta, M. A. Canseco-Martinez, M. Picquart, M. Sanchez, G. Santana","doi":"10.1109/PVSC.2013.6744205","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744205","url":null,"abstract":"In this work we show the different trends in the optoelectronic properties of polymorphous silicon thin films under light-soaking for long exposure times. These thin films were grown by Plasma Enhanced Chemical Vapor Deposition using dichlorosilane as precursor gas and different hydrogen dilutions. When the samples were illuminated by white light at power density of 100 mW/cm2 (AM1.5 condition) during 250 h continuously, singular behaviors on the photoconductivity measurements were shown. The different trends are explained as a function of the crystalline fraction and chemical composition of these films. XPS shows that an oxidation process takes place throughout the film in some samples grown at high hydrogen dilutions, while other samples grown at low hydrogen dilution show only surface oxidation after ambient exposure. In the same way, XPS spectra show different silicon oxidation states and chlorine presence along of the films. On the other hand, FTIR spectra evidence the absence of mono-and dihydride Si-H bonds around 2000-2150 cm-1. These bonds are generally responsible for the degradation process in amorphous silicon thin films solar cells. With the control of the crystalline fractions and chemical composition, it is possible to avoid the degradation process in thin films silicon solar cells. The role of chlorine and hydrogen related bonds, which can be associated with the level of stability of the films, were inferred from XPS and FTIR analysis. Conductivity and photoconductivity changes on polymorphous silicon thin films were observed when the films are subjected to light-soaking for 15000 minutes. These changes are dependent on the chemical and structural properties of the films.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73321737","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744954
Katherine G. Nelson, Sarah K. Brem, C. Foster, S. Bowden, J. Husman, C. Honsberg
The purpose of this work is to discover the misconceptions students have related to PV content, in light of the way in which the content is portrayed curricular tools, namely through simulations. Undergraduate students were recruited from their first circuits courses (N=20) to participate in this study. Participants in the study were presented with PV related content displayed through a simulation previously developed by the PVCDROM. They observed these simulations and were asked associated questions, questions designed to uncover their misconceptions formed as a result of engaging with these simulations. Findings indicate that students hold misconceptions related to both of the simulations utilized; diffusion and drift. The results of this study indicate a need to conduct a deeper level of analysis of the participants' responses, which could potentially provide future evidence related to misconception formation as a result of how simulations related to drift and diffusion are presented using curricular tools. Diffusion and drift should be presented such that it discourages the formation of misconceptions, and ultimately removes barriers to learning PV.
{"title":"Assessing the formation of misconceptions when students learn PV using current curricular tools","authors":"Katherine G. Nelson, Sarah K. Brem, C. Foster, S. Bowden, J. Husman, C. Honsberg","doi":"10.1109/PVSC.2013.6744954","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744954","url":null,"abstract":"The purpose of this work is to discover the misconceptions students have related to PV content, in light of the way in which the content is portrayed curricular tools, namely through simulations. Undergraduate students were recruited from their first circuits courses (N=20) to participate in this study. Participants in the study were presented with PV related content displayed through a simulation previously developed by the PVCDROM. They observed these simulations and were asked associated questions, questions designed to uncover their misconceptions formed as a result of engaging with these simulations. Findings indicate that students hold misconceptions related to both of the simulations utilized; diffusion and drift. The results of this study indicate a need to conduct a deeper level of analysis of the participants' responses, which could potentially provide future evidence related to misconception formation as a result of how simulations related to drift and diffusion are presented using curricular tools. Diffusion and drift should be presented such that it discourages the formation of misconceptions, and ultimately removes barriers to learning PV.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73896681","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744929
S. Saha, R. Rao, L. Mathew, M. Ainom, S. Banerjee
In this work we propose and demonstrate a novel and cost-effective method to fabricate bifacial cells with conventional homojunction architecture. The method combines benefits of lithography-less, self-aligned patterning during deposition of antireflective coating (ARC) and simultaneous metallization of both surfaces aided by electroplating. We have fabricated a conventional diffused n+pp+ junction bifacial solar cell on a monocrystalline silicon (c-Si) substrate using this method. Electrochemically grown nickel is used to simultaneously form front and back electrodes. The bifacial solar cell fabricated with an un-optimized process has a front and rear efficiencies (under AM1.5G one sun illumination) of 12% and 8.66%, respectively. Part of the low performance of the cell is attributed to poor quality of the passivation layer and the post deposition annealing to reduce pinholes in deposited SiNx layer to prevent parasitic plating.
{"title":"A novel low-cost method for fabricating bifacial solar cells","authors":"S. Saha, R. Rao, L. Mathew, M. Ainom, S. Banerjee","doi":"10.1109/PVSC.2013.6744929","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744929","url":null,"abstract":"In this work we propose and demonstrate a novel and cost-effective method to fabricate bifacial cells with conventional homojunction architecture. The method combines benefits of lithography-less, self-aligned patterning during deposition of antireflective coating (ARC) and simultaneous metallization of both surfaces aided by electroplating. We have fabricated a conventional diffused n+pp+ junction bifacial solar cell on a monocrystalline silicon (c-Si) substrate using this method. Electrochemically grown nickel is used to simultaneously form front and back electrodes. The bifacial solar cell fabricated with an un-optimized process has a front and rear efficiencies (under AM1.5G one sun illumination) of 12% and 8.66%, respectively. Part of the low performance of the cell is attributed to poor quality of the passivation layer and the post deposition annealing to reduce pinholes in deposited SiNx layer to prevent parasitic plating.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74127672","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6745072
S. Harb, M. Kedia, Haiyu Zhang, R. Balog
This paper present a comparison between a string inverter based photovoltaic (PV) energy system and a microinverter based system. Reliability, environmental factors, inverter failure, and electrical safety of a test case 6kW residential PV system are thoroughly evaluated and compared using the two different approaches. The impact of all these features on the cost of the PV system is estimated. The results showed that when the levelized cost of energy (LCOE) is considered the break-even cost can be reached by the microinverter more quickly than with a string inverter operating in the same environment Moreover, considering the replacement costs associated with the expected string inverter failure, the microinverter configuration is the more cost effective.
{"title":"Microinverter and string inverter grid-connected photovoltaic system — A comprehensive study","authors":"S. Harb, M. Kedia, Haiyu Zhang, R. Balog","doi":"10.1109/PVSC.2013.6745072","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6745072","url":null,"abstract":"This paper present a comparison between a string inverter based photovoltaic (PV) energy system and a microinverter based system. Reliability, environmental factors, inverter failure, and electrical safety of a test case 6kW residential PV system are thoroughly evaluated and compared using the two different approaches. The impact of all these features on the cost of the PV system is estimated. The results showed that when the levelized cost of energy (LCOE) is considered the break-even cost can be reached by the microinverter more quickly than with a string inverter operating in the same environment Moreover, considering the replacement costs associated with the expected string inverter failure, the microinverter configuration is the more cost effective.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84453830","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744216
Sinae Kim, S. Kasashima, P. Sichanugrist, M. Konagai
We have developed a spectrum splitting type solar cell using a-Si and CIGS as the top and bottom cells, respectively. To increase its performance the top a-Si cell with high Voc and good response at the short wavelength has to be developed. Up to now ZnO has been used as the front TCO. However, since the band gap of ZnO is lower than the one of SnO2, it is better to use SnO2 instead of ZnO. Furthermore, in this splitting solar cell there is no need for front TCO to be much textured. Here we present a initial introduction how to apply commercial and hazy SnO2 to the top cell. Ar treatment has been used in order to flatten the surface of SnO2. As the results high Voc as high as 0.967V has been achieved with smoother SnO2 surface.
{"title":"Application of SnO2 substrate to top cell for spectrum splitting type solar cell","authors":"Sinae Kim, S. Kasashima, P. Sichanugrist, M. Konagai","doi":"10.1109/PVSC.2013.6744216","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744216","url":null,"abstract":"We have developed a spectrum splitting type solar cell using a-Si and CIGS as the top and bottom cells, respectively. To increase its performance the top a-Si cell with high Voc and good response at the short wavelength has to be developed. Up to now ZnO has been used as the front TCO. However, since the band gap of ZnO is lower than the one of SnO2, it is better to use SnO2 instead of ZnO. Furthermore, in this splitting solar cell there is no need for front TCO to be much textured. Here we present a initial introduction how to apply commercial and hazy SnO2 to the top cell. Ar treatment has been used in order to flatten the surface of SnO2. As the results high Voc as high as 0.967V has been achieved with smoother SnO2 surface.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84575484","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744452
S. Tatapudi, F. Ebneali, J. Kuitche, G. Tamizhmani
Potential induced degradation (PID) due to high system voltages is considered as one of the possible degradation mechanisms of PV modules in the field. In the previous studies carried out at ASU-PRL, the surface conductivity of the entire glass was obtained using either conductive carbon layer (covering the entire glass surface and extending it to the frame) or humidity inside an environmental chamber. This study investigates the influence of disruption of glass surface conductivity on the PID. In this study, the conductive carbon layer was applied on the module's glass surface but without extending it to the frame and hence the surface conductivity was disrupted (no carbon layer) at 2 cm distance from the periphery of frame's inner edges. This study was carried out on the modules of different manufacturers under dry heat conditions at multiple stress temperatures and voltages. To replicate closeness to the field-aged modules, half of the selected modules for the PID investigation were pre-stressed under damp heat for 1000 hours and the other half under thermal cycling for 200 cycles. When the surface continuity was disrupted, the degradation was found to be absent or negligibly small even after 35 hours of negative bias at elevated temperatures. This preliminary study appears to indicate that the modules could become immune to PID losses if the continuity of the glass surface conductivity is disrupted at the inside boundary of the frame. The surface conductivity of the glass, due to water layer formation in a humid condition, close to the frame could be disrupted just by applying a transparent hydrophobic layer near the inner edges of the frame or by attaching the frameless laminate with the conductivity disrupting mounting methods such as glue-on rail on the backsheet.
{"title":"Potential induced degradation of pre-stressed photovoltaic modules: Effect of glass surface conductivity disruption","authors":"S. Tatapudi, F. Ebneali, J. Kuitche, G. Tamizhmani","doi":"10.1109/PVSC.2013.6744452","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744452","url":null,"abstract":"Potential induced degradation (PID) due to high system voltages is considered as one of the possible degradation mechanisms of PV modules in the field. In the previous studies carried out at ASU-PRL, the surface conductivity of the entire glass was obtained using either conductive carbon layer (covering the entire glass surface and extending it to the frame) or humidity inside an environmental chamber. This study investigates the influence of disruption of glass surface conductivity on the PID. In this study, the conductive carbon layer was applied on the module's glass surface but without extending it to the frame and hence the surface conductivity was disrupted (no carbon layer) at 2 cm distance from the periphery of frame's inner edges. This study was carried out on the modules of different manufacturers under dry heat conditions at multiple stress temperatures and voltages. To replicate closeness to the field-aged modules, half of the selected modules for the PID investigation were pre-stressed under damp heat for 1000 hours and the other half under thermal cycling for 200 cycles. When the surface continuity was disrupted, the degradation was found to be absent or negligibly small even after 35 hours of negative bias at elevated temperatures. This preliminary study appears to indicate that the modules could become immune to PID losses if the continuity of the glass surface conductivity is disrupted at the inside boundary of the frame. The surface conductivity of the glass, due to water layer formation in a humid condition, close to the frame could be disrupted just by applying a transparent hydrophobic layer near the inner edges of the frame or by attaching the frameless laminate with the conductivity disrupting mounting methods such as glue-on rail on the backsheet.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84720341","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744293
Tao Chen, F. Kohler, A. Heidt, R. Carius, F. Finger
Transparent and conductive microcrystalline silicon carbide (μc-SiC:H) thin films are an excellent window layer for thin film solar cells. For amorphous silicon based solar cells, p-type conductive μc-SiC:H window layers were deposited by the hot-wire chemical vapor deposition (HWCVD) technique. Monomethylsilane (MMS) highly diluted in hydrogen was used as the SiC source in favor of SiC deposition in a stoichiometric form. Aluminum (Al) introduced from Trimethylaluminum (TMAl) was used as the p-type dopant. In this report, the optoelectronic properties of p-type μc-SiC:H thin films prepared with different deposition pressure and filament temperature were investigated. By managing the deposition parameters, materials with optical gap E04 ranging from 2.0 eV to 2.8 eV and dark conductivity ranging from 10-5 S/cm to 0.1 S/cm were prepared. Such p-type μc-SiC:H thin films were applied as the window layer in amorphous silicon thin film silicon solar cells. Taking advantage of the high transparency of μc-SiC:H window layer, improved quantum efficiency was obtained at the short wavelength below 500 nm.
{"title":"Highly transparent and conductive p-type microcrystalline silicon carbide window layers for thin film silicon solar cells","authors":"Tao Chen, F. Kohler, A. Heidt, R. Carius, F. Finger","doi":"10.1109/PVSC.2013.6744293","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744293","url":null,"abstract":"Transparent and conductive microcrystalline silicon carbide (μc-SiC:H) thin films are an excellent window layer for thin film solar cells. For amorphous silicon based solar cells, p-type conductive μc-SiC:H window layers were deposited by the hot-wire chemical vapor deposition (HWCVD) technique. Monomethylsilane (MMS) highly diluted in hydrogen was used as the SiC source in favor of SiC deposition in a stoichiometric form. Aluminum (Al) introduced from Trimethylaluminum (TMAl) was used as the p-type dopant. In this report, the optoelectronic properties of p-type μc-SiC:H thin films prepared with different deposition pressure and filament temperature were investigated. By managing the deposition parameters, materials with optical gap E04 ranging from 2.0 eV to 2.8 eV and dark conductivity ranging from 10-5 S/cm to 0.1 S/cm were prepared. Such p-type μc-SiC:H thin films were applied as the window layer in amorphous silicon thin film silicon solar cells. Taking advantage of the high transparency of μc-SiC:H window layer, improved quantum efficiency was obtained at the short wavelength below 500 nm.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84770504","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744392
B. Conley, A. Mosleh, S. Ghetmiri, H. Naseem, J. Tolle, Shui-Qing Yu
Multi-junction solar cell efficiency gains due to GeSn and SiGeSn have already shown that a need exists for significant advancement in growing this material in a commercially available CVD chamber. Ge1-xSnx films have been grown via an Epsilon RPCVD single wafer CVD deposition tool on Si using a relaxed Ge buffer layer. The material and optical properties of these films have been characterized for various compositions. We present the characterization of strained Ge1-xSnx with x = 0.9 % to 7 % and photoluminescence of Ge1-xSnx grown via a commercial CVD reactor. This commercial growth accessibility shows that this ternary material should allow for further advancements in multi-junction photovoltaics using Si CMOS compatible processes.
{"title":"CVD growth of Ge1−xSnx using large scale Si process for higher efficient multi-junction solar cells","authors":"B. Conley, A. Mosleh, S. Ghetmiri, H. Naseem, J. Tolle, Shui-Qing Yu","doi":"10.1109/PVSC.2013.6744392","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744392","url":null,"abstract":"Multi-junction solar cell efficiency gains due to GeSn and SiGeSn have already shown that a need exists for significant advancement in growing this material in a commercially available CVD chamber. Ge1-xSnx films have been grown via an Epsilon RPCVD single wafer CVD deposition tool on Si using a relaxed Ge buffer layer. The material and optical properties of these films have been characterized for various compositions. We present the characterization of strained Ge1-xSnx with x = 0.9 % to 7 % and photoluminescence of Ge1-xSnx grown via a commercial CVD reactor. This commercial growth accessibility shows that this ternary material should allow for further advancements in multi-junction photovoltaics using Si CMOS compatible processes.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85025215","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}
Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744466
T. Chong, K. Weber, A. Blakers
We present a reliable and cost effective 2-step metal-assisted-etching (MAE) texturing technique that forms random-micropores. The optical behavior of the random-micropores is systematically studied. We demonstrate that the random-micropore morphology is capable of suppressing front surface reflection more efficiently than not only the conventional acidic texturing but also the widely used random pyramid texture. We demonstrate that the angular reflectance distribution of our random-micropores is intermediate between isotexture and random upright pyramid structures. These results strongly suggest that the random-nanopore texture can outperform isotexture and random upright pyramid morphology when encapsulated. Due to its nano-scale feature size, it can be used for texturing both mono-crystalline (c-si) and multi-crystalline (mc-si) silicon solar cells, as well as non-conventional thin Si solar cells such as SLIVER cells that feature surfaces that cannot easily be textured using established texturing techniques. The uniformity and reproducibility of the morphology have also been verified.
{"title":"Forming random-micropores by optimized 2-step metal assisted etching process","authors":"T. Chong, K. Weber, A. Blakers","doi":"10.1109/PVSC.2013.6744466","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744466","url":null,"abstract":"We present a reliable and cost effective 2-step metal-assisted-etching (MAE) texturing technique that forms random-micropores. The optical behavior of the random-micropores is systematically studied. We demonstrate that the random-micropore morphology is capable of suppressing front surface reflection more efficiently than not only the conventional acidic texturing but also the widely used random pyramid texture. We demonstrate that the angular reflectance distribution of our random-micropores is intermediate between isotexture and random upright pyramid structures. These results strongly suggest that the random-nanopore texture can outperform isotexture and random upright pyramid morphology when encapsulated. Due to its nano-scale feature size, it can be used for texturing both mono-crystalline (c-si) and multi-crystalline (mc-si) silicon solar cells, as well as non-conventional thin Si solar cells such as SLIVER cells that feature surfaces that cannot easily be textured using established texturing techniques. The uniformity and reproducibility of the morphology have also been verified.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85076554","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}
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