镁掺杂对铜锌锡硒薄膜太阳能电池性能的影响

本项目拟通过Mg2+离子部分取代Zn2+离子来抑制铜锌锡硒（Cu2ZnSnSe4,简称CZTSe）材料中有害缺陷的产生，改善该材料的光电性能；通过引入Mg2+离子构造具有能带梯度的CZTSe吸光层，提高CZTSe电池的性能。在石英衬底上，我们初步研究了Mg2+掺杂对Cu2ZnSnSe4晶体晶胞参数、薄膜形貌以及薄膜载流子浓度的影响。下一步我们将系统地研究Mg2+掺杂对CZTSe薄膜太阳能电池性能的影响。本项目的创新之处：(1) 利用低毒、环保、地壳元素含量丰富的Mg2+部分取代Zn2+，有利于抑制CZTSe材料中CuZn不良缺陷的产生，改善材料的光电性能；(2) 通过Mg2+掺杂制备有能带梯度的CZTSe薄膜，构建出具有最佳“V”型能带结构的CZTSe吸收层，实现电池的光电转换效率超过11%。

This project proposes that Zn2+ ions are substituted partially by Mg2+ ions to restrain the unfavorable defects in the Cu2ZnSnSe4 (CZTSe) compound, optimizing its optoelectronic properties. Mg-doping is useful to fabricate V-type band gradient of CZTSe absorber layer, which would improve the performance of CZTSe solar cells further. Based on the quartz substrate, we have preliminarily studied the effects of Mg-doping on the lattice parameters of CZTSe crystal grains, the morphology of CZTSe thin films, and its effective hole-carrier concentration. Next, the effects of Mg-doing on the performance of the CZTSe devices will be studied systematically. The novelties of this project are as follows：(1) Due to its advantages of non-toxic, environmental-friendly, and earth- abundant element, Mg2+ ions can partially replace Zn2+ ions, helpful for restraining the unfavorable defects of CuZn in the CZTSe compound, optimizing its optoelectronic properties; (2) CZTSe thin films possessed various band gradients can be prepared via Mg-doping, and CZTSe absorber layer with the optimal V-type band gradient can be constructed, obtaining the photoelectric conversion efficiency over 11% of the devices.