Sabbah Hussein
College of Engineering and Technology, American University of the Middle East, Kuwait.
Materials (Basel). 2022 Apr 29;15(9):3229. doi: 10.3390/ma15093229.
A cesium tin−germanium triiodide (CsSnGeI3) perovskite-based solar cell (PSC) has been reported to achieve a high-power-conversion efficiency (PCE > 7%) and extreme air stability. A thorough understanding of the role of the interfaces in the perovskite solar cell, along with the optimization of different parameters, is still required for further improvement in PCE. In this study, lead-free CsSnGeI3 PSC has been quantitatively analyzed using a solar cell capacitance simulator (SCAPS−1D). Five electron transport layers (ETL) were comparatively studied, while keeping other layers fixed. The use of SnO2 as an ETL, which has the best band alignment with the perovskite layer, can increase the power conversion efficiency (PCE) of PSC by up to 30%. The defect density and thickness of the absorber layer has been thoroughly investigated. Results show that the device efficiency is highly governed by the defect density of the absorber layer. All the PSCs with a different ETL exhibit PCE exceeding 20% when the defect density of the absorber layer is in the range of 1014 cm−3−1016 cm−3, and degrade dramatically at higher values. With the optimized structure, the simulation found the highest PCE of CsSnGeI3-based PSCs to be 30.98%, with an open circuit voltage (Voc) of 1.22 V, short-circuit current density (Jsc) of 28.18 mA·cm−2, and fill factor (FF) of 89.52%. Our unprecedented results clearly demonstrate that CsSnGeI3-based PSC is an excellent candidate to become the most efficient single-junction solar cell technology soon.
据报道，基于铯锡锗三碘化物（CsSnGeI3）钙钛矿的太阳能电池（PSC）可实现高功率转换效率（PCE>7%）和极高的空气稳定性。为了进一步提高功率转换效率，仍需要深入了解钙钛矿太阳能电池中界面的作用，并优化不同参数。在本研究中，使用太阳能电池电容模拟器（SCAPS-1D）对无铅CsSnGeI3 PSC进行了定量分析。在保持其他层固定的情况下，对五种电子传输层（ETL）进行了比较研究。使用与钙钛矿层具有最佳能带对准的SnO2作为ETL，可将PSC的功率转换效率（PCE）提高多达30%。对吸收层的缺陷密度和厚度进行了深入研究。结果表明，器件效率高度受吸收层缺陷密度的影响。当吸收层的缺陷密度在1014 cm−3至1016 cm−3范围内时，所有具有不同ETL的PSC的PCE均超过20%，而在更高的值时则会急剧下降。通过优化结构，模拟发现基于CsSnGeI3的PSC的最高PCE为30.98%，开路电压（Voc）为1.22 V，短路电流密度（Jsc）为28.18 mA·cm−2，填充因子（FF）为89.52%。我们前所未有的结果清楚地表明，基于CsSnGeI3的PSC是一种优秀的候选材料，有望很快成为最高效的单结太阳能电池技术。
