Effect of oxygen vacancies in the electron transfer layer SiZnSnO on the performance of perovskite solar cells

Abstract

Abstract In recent years, perovskite solar cells with low cost and high efficiency are developing rapidly. In view of the potential commercialization of perovskite solar cells, it is very important to upgrade its functional layer. ZnSnO (ZTO) has the advantages of high transmittance, so it is often used as the electron transport layer of solar cells. Oxygen vacancies in ZTO not only plays the role of carrier, but also is the main defect in ZTO. So we study the impact of oxygen vacancies in ZTO to solar cells by preparing ZTO solar cells with different Si doping concentrations. In this work, the amorphous metal oxide films Si–ZnSnO (SZTO) with different Si concentrations were prepared by RF magnetron sputtering. The XPS results indicate that the oxygen vacancies density in SZTO can be significantly reduced by Si doping. The carrier dynamics studies found that the electronic extraction and transfer ability of perovskite solar cell can be also improved with the reduction of oxygen vacancies in SZTO. With an improved electron transfer layer, the perovskite solar cell has a maximum photoelectric conversion efficiency of 13.4%, an open circuit voltage of 1.04 V and a short circuit current of 21.6 mAcm−2. Filling factor is 0.67.