Zhang Bingye, Han Lu, Ying Shitian, Li Yongfeng, Yao Bin
Department of Physics, Dalian University of Technology Dalian Liaoning 116023 P. R. China
Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University Changchun 130012 China
RSC Adv. 2018 May 24;8(34):19213-19219. doi: 10.1039/c8ra03437k. eCollection 2018 May 22.
Reducing interface recombination losses is one of the major challenges in developing CuZnSn(S,Se) (CZTSSe) solar cells. Here, we propose a CZTSSe solar cell with an atomic layer deposited AlO thin film for surface passivation. The influence of passivation layer thickness on the power conversion efficiency (PCE), short-circuit current density ( ), open-circuit voltage ( ) and fill factor (FF) of the solar cell is systematically investigated. It is found that the AlO film presents notable antireflection (AR) properties over a broad range of wavelengths (350-1000 nm) for CZTSSe solar cells. With increasing AlO thickness (1-10 nm), the average reflectance of the CZTSSe film decreases from 12.9% to 9.6%, compared with the average reflectance of 13.6% for the CZTSSe film without AlO. The AlO passivation layer also contributes to suppressed surface recombination and enhanced carrier separation. Passivation performance is related to chemical and field effect passivation, which is due to released H atoms from the Al-OH bonds and the formation of Al vacancies and O interstitials within AlO films. Therefore, the and of the CZTSSe solar cell with 2 nm-AlO were increased by 37.8% and 57.8%, respectively, in comparison with those of the unpassivated sample. An optimal CZTSSe solar cell was obtained with a , and of 0.361 V, 33.78 mA and 5.66%. Our results indicate that AlO films show the dual functions of AR and surface passivation for photovoltaic applications.
降低界面复合损失是开发铜锌锡（硫，硒）（CZTSSe）太阳能电池的主要挑战之一。在此，我们提出一种具有原子层沉积AlO薄膜用于表面钝化的CZTSSe太阳能电池。系统研究了钝化层厚度对太阳能电池功率转换效率（PCE）、短路电流密度（ ）、开路电压（ ）和填充因子（FF）的影响。发现AlO薄膜在CZTSSe太阳能电池的宽波长范围（350 - 1000 nm）内呈现出显著的抗反射（AR）特性。随着AlO厚度增加（1 - 10 nm），CZTSSe薄膜的平均反射率从12.9%降至9.6%，而未加AlO的CZTSSe薄膜平均反射率为13.6%。AlO钝化层还有助于抑制表面复合并增强载流子分离。钝化性能与化学和场效应钝化有关，这是由于Al - OH键释放出H原子以及在AlO薄膜中形成Al空位和O间隙。因此，与未钝化样品相比，具有2 nm - AlO的CZTSSe太阳能电池的 和 分别提高了37.8%和57.8%。获得了一个最佳的CZTSSe太阳能电池，其 、 和 分别为0.361 V、33.78 mA和5.66%。我们的结果表明，AlO薄膜在光伏应用中展现出抗反射和表面钝化的双重功能。
