Department of Chemistry and James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.
Nano Lett. 2014 Feb 12;14(2):670-5. doi: 10.1021/nl403912w. Epub 2014 Jan 6.
Solution processing of photovoltaic semiconducting layers offers the potential for drastic cost reduction through improved materials utilization and high device throughput. One compelling solution-based processing strategy utilizes semiconductor layers produced by sintering nanocrystals into large-grain semiconductors at relatively low temperatures. Using n-ZnO/p-CdTe as a model system, we fabricate sintered CdTe nanocrystal solar cells processed at 350 °C with power conversion efficiencies (PCE) as high as 12.3%. JSC of over 25 mA cm(-2) are achieved, which are comparable or higher than those achieved using traditional, close-space sublimated CdTe. We find that the VOC can be substantially increased by applying forward bias for short periods of time. Capacitance measurements as well as intensity- and temperature-dependent analysis indicate that the increased VOC is likely due to relaxation of an energetic barrier at the ITO/CdTe interface.
光伏半导体层的溶液处理通过提高材料利用率和高器件吞吐量，提供了大幅降低成本的潜力。一种引人注目的基于溶液的处理策略是利用在相对较低温度下将纳米晶烧结成大晶粒半导体的半导体层。我们使用 n-ZnO/p-CdTe 作为模型体系，在 350°C 下制备烧结的 CdTe 纳米晶太阳能电池，其功率转换效率（PCE）高达 12.3%。实现了超过 25 mA cm(-2) 的 JSC，与使用传统的近空间升华 CdTe 获得的数值相当或更高。我们发现，通过施加短时间的正向偏压，可以大大提高 VOC。电容测量以及强度和温度相关分析表明，增加的 VOC 可能是由于在 ITO/CdTe 界面处的能量势垒的松弛。
