Investigation of the Sub‐Bandgap Photoresponse in CuGaS2 : Fe for Intermediate Band Solar Cells
Investigation of the Sub‐Bandgap Photoresponse in CuGaS2 : Fe for Intermediate Band Solar Cells
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DOI：
10.4229/26theupvsec2011-1ao.8.5
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发表时间：
2011-10
期刊：
影响因子：
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通讯作者：
B. Marsen;S. Klemz;T. Unold;H. Schock
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文献类型：
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作者：
B. Marsen;S. Klemz;T. Unold;H. Schock
过渡金属掺杂黄铜矿薄膜已被提议作为中波段太阳能电池的合适吸收材料。在这项工作中，CuGa1−xFexS2 薄膜是通过真空共蒸发在 400 °C 的基板温度下生长的，并掺入了不同量的 Fe。通过透射率/反射率测量来评估在钠钙玻璃上生长的薄膜的光学响应。光伏器件是由 CuGa1−xFexS2 薄膜制成的，同时使用标准黄铜矿玻璃/Mo/吸收剂/CdS/ZnO 器件结构沉积在镀 Mo 的玻璃基板上。通过电流电压和量子效率测量来评估这些太阳能电池的器件特性。对于含 Fe 的 CuGaS2 薄膜，在 1·2 eV 和 1·9 eV 处检测到明显的亚能隙吸收带，并且随着 Fe 含量的增加而变得更加突出。另一方面，发现太阳能电池参数随着铁含量的增加而恶化，这表明当掺入高含量的铁时非辐射复合增加。然而，对于最低的铁含量（x = 0·003），观察到亚能隙光响应在约1·9 eV处增加，这是由于在此稀释水平下充分的中间带吸收和载流子收集的组合。版权所有 © 2011 约翰·威利父子有限公司
Transition-metal doped chalcopyrite thin films have been proposed as a suitable absorber material for intermediate band solar cells. In this work, CuGa1−xFexS2 thin films were grown by vacuum co-evaporation at a substrate temperature of 400 °C with various amounts of incorporated Fe. The optical response of thin films grown on soda-lime glass was evaluated by transmittance/reflectance measurements. Photovoltaic devices were fabricated from CuGa1−xFexS2 thin films concurrently deposited on Mo-coated glass substrates using the standard chalcopyrite glass/Mo/absorber/CdS/ZnO device structure. The device characteristics of these solar cells were evaluated by current–voltage and quantum efficiency measurements. For Fe-containing CuGaS2 films, distinct sub-gap absorption bands at 1·2 eV and 1·9 eV are detected, which increase in prominence with increasing Fe content. On the other hand, the solar cell parameters were found to deteriorate with increasing iron content, indicating an increase in non-radiative recombination when high levels of iron are incorporated. However, for the lowest iron content (x = 0·003), an increase in the sub-gap photoresponse at about 1·9 eV is observed, which is attributed to a combination of sufficient intermediate band absorption and carrier collection at this dilution level. Copyright © 2011 John Wiley & Sons, Ltd.