摘要
Although low-temperature, solution-processed zinc oxide(ZnO) has been widely adopted as the electron collection layer(ECL) in perovskite solar cells(PSCs) because of its simple synthesis and excellent electrical properties such as high charge mobility, the thermal stability of perovskite films deposited atop ZnO layers remains as a major issue.Herein, we report a strategy of low-temperature TiO_2 surfice modification to ZnO nanoparticle(NP) layers for alleviate the issue.Based on the proposed strategy, an overall power conversion efficiency(PCE) of 15% has been achieved mainly due to the improved open-circuit voltage(V_(oc)) of 1.06 V, short-circuit current density(J_(sc)) of 19.1mA cm~(-2), and fill factor(FF) of 0.74, which are much higher than those of bare ZnO NPs-based devices.More importantly, the perovskite solar cells based on low-temperature TiO_2 modified ZnO ECLs may retain 80% of their initial performance after 750 hours of atmosphere storage, showing much higher device stability.Due to the fact that the entire device fabrication can be processed at less than 150℃, it is expected that the surface modified ZnO film developed here may be employed as an effective ETL of low temperature processed, efficient and stable PSCs that are compatible with flexible electronics.
Although low-temperature, solution-processed zinc oxide(ZnO) has been widely adopted as the electron collection layer(ECL) in perovskite solar cells(PSCs) because of its simple synthesis and excellent electrical properties such as high charge mobility, the thermal stability of perovskite films deposited atop ZnO layers remains as a major issue.Herein, we report a strategy of low-temperature TiO_2 surfice modification to ZnO nanoparticle(NP) layers for alleviate the issue.Based on the proposed strategy, an overall power conversion efficiency(PCE) of 15% has been achieved mainly due to the improved open-circuit voltage(V_(oc)) of 1.06 V, short-circuit current density(J_(sc)) of 19.1mA cm~(-2), and fill factor(FF) of 0.74, which are much higher than those of bare ZnO NPs-based devices.More importantly, the perovskite solar cells based on low-temperature TiO_2 modified ZnO ECLs may retain 80% of their initial performance after 750 hours of atmosphere storage, showing much higher device stability.Due to the fact that the entire device fabrication can be processed at less than 150℃, it is expected that the surface modified ZnO film developed here may be employed as an effective ETL of low temperature processed, efficient and stable PSCs that are compatible with flexible electronics.
引文
[1]Xingyue Zhao,Heping Shen,Ye Zhang,Xin Li,Xiaochong Zhao,Meiqian Tai,Jingfeng Li,Jianbao Li,Xin Li and Hong Lin,ACS Appl.Mater.Interfaces 2016,8,7826-7833.
[2]Junghwan Kim,Geunjin Kim,Tae Kyun Kim,Sooncheol Kwon,Hyungcheol Back,Jinho Lee,a Seoung Ho Lee,Hongkyu Kangb and Kwanghee Lee,J.Mater.Chem.A,2014,2,17291–17296.