TiO2 passivation for improved efficiency and stability of ZnO nanorods based perovskite solar cells. Issue 63 (16th June 2016)

• Record Type: Journal Article
• Authors: Chen, Peng; Yin, Xingtian; Que, Meidan; Yang, Yawei; Que, Wenxiu
• Is Part Of: RSC advances. Volume 6:Issue 63(2016)
• Page Start: 57996
• Page End: 58002
• Publication Date: 2016-06-16
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra12126h
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : We adopted a wet-chemical method to deposit a TiO2 passivation layer on ZnO nanorods, and demonstrated drastically improved photovoltaic performance and device stability of ZnO nanorods based perovskite solar cells. Abstract : Zinc oxide (ZnO) has been demonstrated to be a superb electron selective contact material in photovoltaic devices for its high electron mobility and various accessible nanostructures. However, issues of severe charge recombination and thermal instability occurring at the perovskites/ZnO interface hinder its application on perovskite solar cells. Herein, we report a strategy of TiO2 passivation onto the surface of ZnO nanorods (NRs) using a wet-chemical method, where a device structure FTO/ZnO NRs/TiO2 passivation layer/CH3 NH3 PbI3 /spiro-OMeTAD/Ag is adopted. Based on the proposed strategy, an overall power conversion efficiency (PCE) of 13.49% is achieved mainly due to the improved open-circuit voltage ( V oc ) of 1.02 V, shirt-circuit current density ( J sc ) of 20.69 mA cm −2, and fill factor (FF) of 0.64, which are much higher than those of bare ZnO NRs-based devices. Interestingly, TiO2 passivated samples show much better long-term device stability than those without passivation, where TiO2 acts as a buffer layer with improved thermal stability owning to reduced chemisorbed hydroxyl groups as indicated by X-ray photoelectron spectroscopy.