Study of In S and ZnS thin films deposition by ultrasonic spray pyrolysis and chemical deposition... more Study of In S and ZnS thin films deposition by ultrasonic spray pyrolysis and chemical deposition 2 3 This thesis is focused on studies of ultrasonic spray pyrolysis deposition of In2S3 thin films and chemical bath deposition of ZnS thin films as alternative buffer layers to CBD-CdS for CuInSe2 type absorber materials in PV solar cells. The first part of the study describes the process of replacing CBD CdS buffer layers in Cu(In,Ga)Se2 solar cells by In2S3 thin film buffer layers deposited by an ultrasonic spray pyrolysis method. USP-In2S3 films were prepared at various substrate temperatures (200, 220 and 245 C) and spray solution concentrations. Thin USP-In2S3 films properties were studied with several techniques including profilometer, spectro-photometer, XPS, XRD, and SEM. USP-In2S3/CIGSe solar cells were studied by measuring their I-V characteristics and by EQE measurements. The growth rate of the In2S3 film was studied and it was found to increase with increasing substrate tem...
Advances in Materials Science and Engineering, 2009
The study on the anion effect of different Zn sources—Zn(CH3COO)2, ZnCl2, ZnI2, Zn(NO3)2and ZnSO4... more The study on the anion effect of different Zn sources—Zn(CH3COO)2, ZnCl2, ZnI2, Zn(NO3)2and ZnSO4—on the chemical deposition of ZnS(O,OH) films revealed that the growth rate and composition of the ZnS(O,OH) layer depend on the instability constant (pK) value of the corresponding Zn-complex Zn(L)nin the chemical bath solution. In the region ofpKZn(NH3)2+>pKZn(L)nthe ZnS(O,OH) film's growth rate and ZnS concentration in films increased with the increasing pK value of the used Zn salt complex up to the pK value of theZn[NH3]2+complex and decreased in the region wherepKZn(NH3)2+<pKZn(L)n. The band gap values (around 3.6 eV in most cases) of deposited ZnS(O,OH) films did not depend on the Zn precursor's instability constant, the ZnS(O,OH) film from zinc nitrate containing bath has higher band gap energy (Eg= 3.8 eV). The maximum efficiency of CISSe and CZTSSe monograin layer solar cells was gained with ZnS(O,OH) buffer layer deposited from CBD solution containing Zn(CH3COO)...
ABSTRACT Ternary semiconductor compound CuInSe2 is one of the most promising absorber material us... more ABSTRACT Ternary semiconductor compound CuInSe2 is one of the most promising absorber material used in solar cells. In this study, we used CuInSe2 powder materials synthesized in molten salts. Modifying the preparation conditions, we studied the relationships between the initial and final composition, and determined the preparation conditions for the single- phase growth of CuInSe2. The as-grown samples were annealed in selenium or sulfur vapor at various temperatures for a different time period to change the CuInSe2 material properties. Se vapor treatment has been found to influence the bulk composition. Sulfur vapor treatment has been found to improve the open-circuit voltage of the completed cells by about 100 mV. It could be attributed to an increase of the band gap at the surface of the absorber due to the formation of a wider band gap CuIn(S,Se)2 material. The incorporation of sulfur into CuInSe2 reduces the carrier recombination in the interface region, which was indicated as an improvement of the fill factor of the cells.
To verify the positive effect of thin tin oxide layer on the surface of CZTS to solar cell VOC, a... more To verify the positive effect of thin tin oxide layer on the surface of CZTS to solar cell VOC, a thin layer of SnOx was deposited onto the CZTS mono grains by ALD. For confirmation of the effect, the SnOx layer was tested in combination with two different buffer materials - CBD CdS and ZnO,S. The deposition of a SnOx inter-layer resulted in increased VOC of CZTS/CdS solar cell from 666 mV to 724 mV and CZTS/ZnO,S solar cell from 617 mV to 719 mV. The tin oxide layer did not affect the FF and jSC values, so the improvement in VOC led to a direct improvement in CZTS/CdS solar cell PCE. EQE measurements did not show any shift in material absorption edge/band gap, hence the VOC increase can be fully attributed to the interface improvements, like to a reduced interface recombination rate. Apparently the additional SnOx layer seems to allow for better collection of the carriers at longer wavelength region (650 nm - 750 nm).
Copper zinc tin sulfo-selenide Cu2ZnSn(SSe)4 (CZTS) is a low-cost alternative semiconductor mater... more Copper zinc tin sulfo-selenide Cu2ZnSn(SSe)4 (CZTS) is a low-cost alternative semiconductor material used as absorber in solar cells. CZTS monograins approach was considered to be a potential candidate for futuristic low-cost production technology of solar panels. For CZTS (and also CIGS) solar cell, CdS deposited by chemical bath deposition (CBD) is still the most efficient buffer layer. However, development of Cd-free buffer layer is hugely demanded in perspective scaling-up production of CZTS and CIGS solar cells due to the harmfullness of Cd. In this work, we report on synthesis and use of a zinc-based buffer layer for CZTS monograin solar cell. Zn-based buffer layer was deposited onto CZTS absorber layer by employing a simple, non-vacuum and scalable CBD method. Morphology and chemical composition of the ZnS(O,OH) film was characterized by SEM, XPS and Raman spectroscopies. Effect of thickness, morphology as well as chemical composition of the deposited ZnS(O,OH) buffer layer o...
Abstract A chemical method for the incorporation of copper into indium gallium selenide (IGS) lay... more Abstract A chemical method for the incorporation of copper into indium gallium selenide (IGS) layers has been developed. The resulting copper-containing precursor layers have been annealed in the presence of selenium vapour with the goal of forming Cu (In, Ga) Se ...
Study of In S and ZnS thin films deposition by ultrasonic spray pyrolysis and chemical deposition... more Study of In S and ZnS thin films deposition by ultrasonic spray pyrolysis and chemical deposition 2 3 This thesis is focused on studies of ultrasonic spray pyrolysis deposition of In2S3 thin films and chemical bath deposition of ZnS thin films as alternative buffer layers to CBD-CdS for CuInSe2 type absorber materials in PV solar cells. The first part of the study describes the process of replacing CBD CdS buffer layers in Cu(In,Ga)Se2 solar cells by In2S3 thin film buffer layers deposited by an ultrasonic spray pyrolysis method. USP-In2S3 films were prepared at various substrate temperatures (200, 220 and 245 C) and spray solution concentrations. Thin USP-In2S3 films properties were studied with several techniques including profilometer, spectro-photometer, XPS, XRD, and SEM. USP-In2S3/CIGSe solar cells were studied by measuring their I-V characteristics and by EQE measurements. The growth rate of the In2S3 film was studied and it was found to increase with increasing substrate tem...
Advances in Materials Science and Engineering, 2009
The study on the anion effect of different Zn sources—Zn(CH3COO)2, ZnCl2, ZnI2, Zn(NO3)2and ZnSO4... more The study on the anion effect of different Zn sources—Zn(CH3COO)2, ZnCl2, ZnI2, Zn(NO3)2and ZnSO4—on the chemical deposition of ZnS(O,OH) films revealed that the growth rate and composition of the ZnS(O,OH) layer depend on the instability constant (pK) value of the corresponding Zn-complex Zn(L)nin the chemical bath solution. In the region ofpKZn(NH3)2+>pKZn(L)nthe ZnS(O,OH) film's growth rate and ZnS concentration in films increased with the increasing pK value of the used Zn salt complex up to the pK value of theZn[NH3]2+complex and decreased in the region wherepKZn(NH3)2+<pKZn(L)n. The band gap values (around 3.6 eV in most cases) of deposited ZnS(O,OH) films did not depend on the Zn precursor's instability constant, the ZnS(O,OH) film from zinc nitrate containing bath has higher band gap energy (Eg= 3.8 eV). The maximum efficiency of CISSe and CZTSSe monograin layer solar cells was gained with ZnS(O,OH) buffer layer deposited from CBD solution containing Zn(CH3COO)...
ABSTRACT Ternary semiconductor compound CuInSe2 is one of the most promising absorber material us... more ABSTRACT Ternary semiconductor compound CuInSe2 is one of the most promising absorber material used in solar cells. In this study, we used CuInSe2 powder materials synthesized in molten salts. Modifying the preparation conditions, we studied the relationships between the initial and final composition, and determined the preparation conditions for the single- phase growth of CuInSe2. The as-grown samples were annealed in selenium or sulfur vapor at various temperatures for a different time period to change the CuInSe2 material properties. Se vapor treatment has been found to influence the bulk composition. Sulfur vapor treatment has been found to improve the open-circuit voltage of the completed cells by about 100 mV. It could be attributed to an increase of the band gap at the surface of the absorber due to the formation of a wider band gap CuIn(S,Se)2 material. The incorporation of sulfur into CuInSe2 reduces the carrier recombination in the interface region, which was indicated as an improvement of the fill factor of the cells.
To verify the positive effect of thin tin oxide layer on the surface of CZTS to solar cell VOC, a... more To verify the positive effect of thin tin oxide layer on the surface of CZTS to solar cell VOC, a thin layer of SnOx was deposited onto the CZTS mono grains by ALD. For confirmation of the effect, the SnOx layer was tested in combination with two different buffer materials - CBD CdS and ZnO,S. The deposition of a SnOx inter-layer resulted in increased VOC of CZTS/CdS solar cell from 666 mV to 724 mV and CZTS/ZnO,S solar cell from 617 mV to 719 mV. The tin oxide layer did not affect the FF and jSC values, so the improvement in VOC led to a direct improvement in CZTS/CdS solar cell PCE. EQE measurements did not show any shift in material absorption edge/band gap, hence the VOC increase can be fully attributed to the interface improvements, like to a reduced interface recombination rate. Apparently the additional SnOx layer seems to allow for better collection of the carriers at longer wavelength region (650 nm - 750 nm).
Copper zinc tin sulfo-selenide Cu2ZnSn(SSe)4 (CZTS) is a low-cost alternative semiconductor mater... more Copper zinc tin sulfo-selenide Cu2ZnSn(SSe)4 (CZTS) is a low-cost alternative semiconductor material used as absorber in solar cells. CZTS monograins approach was considered to be a potential candidate for futuristic low-cost production technology of solar panels. For CZTS (and also CIGS) solar cell, CdS deposited by chemical bath deposition (CBD) is still the most efficient buffer layer. However, development of Cd-free buffer layer is hugely demanded in perspective scaling-up production of CZTS and CIGS solar cells due to the harmfullness of Cd. In this work, we report on synthesis and use of a zinc-based buffer layer for CZTS monograin solar cell. Zn-based buffer layer was deposited onto CZTS absorber layer by employing a simple, non-vacuum and scalable CBD method. Morphology and chemical composition of the ZnS(O,OH) film was characterized by SEM, XPS and Raman spectroscopies. Effect of thickness, morphology as well as chemical composition of the deposited ZnS(O,OH) buffer layer o...
Abstract A chemical method for the incorporation of copper into indium gallium selenide (IGS) lay... more Abstract A chemical method for the incorporation of copper into indium gallium selenide (IGS) layers has been developed. The resulting copper-containing precursor layers have been annealed in the presence of selenium vapour with the goal of forming Cu (In, Ga) Se ...
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