Perovskite Solar Cells with ZnO Electron‐Transporting Materials

Abstract

Perovskite solar cells (PSCs) have developed rapidly over the past few years, and the power conversion efficiency of PSCs has exceeded 20%. Such high performance can be attributed to the unique properties of perovskite materials, such as high absorption over the visible range and long diffusion length. Due to the different diffusion lengths of holes and electrons, electron transporting materials (ETMs) used in PSCs play a critical role in PSCs performance. As an alternative to TiO ETM, ZnO materials have similar physical properties to TiO but with much higher electron mobility. In addition, there are many simple and facile methods to fabricate ZnO nanomaterials with low cost and energy consumption. This review focuses on recent developments in the use of ZnO ETM for PSCs. The fabrication methods of ZnO materials are briefly introduced. The influence of different ZnO ETMs on performance of PSCs is then reviewed. The limitations of ZnO ETM-based PSCs and some solutions to these challenges are also discussed. The review provides a systematic and comprehensive understanding of the influence of different ZnO ETMs on PSCs performance and potentially motivates further development of PSCs by extending the knowledge of ZnO-based PSCs to TiO -based PSCs.

Nonsiliceous Mesoporous Materials: Design and Applications in Energy Conversion and Storage

“…For high performance solar cells, electron transfer materials should meet the following criteria: a) good optical transmittance in the visible range, which reduces the optical energy loss; b) matching of the energy levels of the electron transfer material with that of perovskite materials, which improves the electron extraction efficiency and blocks holes; c) good electron mobility; and d) easy fabrication of a high‐quality film. TiO 2 , SnO 2 , and ZnO have been the three most commonly mentioned materials . As the most applied material for the electron transfer layer, TiO 2 has shown unavoidable shortcomings of high‐temperature annealing and low electron mobility.…”

Suppressed Decomposition of Perovskite Film on ZnO Via a Self‐Assembly Monolayer of Methoxysilane

“…Perovskite films on ZnO decompose rapidly due to the proton transfer of methylammonium (MA) cation caused by the nature of ZnO surface, and the decomposition is accelerated due to its more violent molecule motion at high temperature . Moreover, there are also a lot of hydroxyl groups or chemical residuals on the low‐temperature process ZnO surface, causing accelerated degradation of perovskite film . Interface Engineering between perovskite and ZnO is the common method to reduce the effect of ZnO surface on perovskite and improve the stability of perovskite.…”

Enhanced Lifetime and Photostability with Low‐Temperature Mesoporous ZnTiO3/Compact SnO2Electrodes in Perovskite Solar Cells

“…[9] Among various structures,S nO 2 -ETLs shows better application potential [10] than the traditional TiO 2 -ETL (generally requires high annealing temperature to rutile phase) [11] for their good performance and facile process,especially the ultraviolet light (UV)-inert characters.Asthe strong photocatalytic activity of TiO 2 often leads to unstable operating state and hysteresis current-voltage curves of PSCs,t he UV-inert SnO 2 -ETLs now are widely used in PSCs.Asuitable ETL should meet some basic requirements for high device efficiency. [12] SnO 2 -based devices typically require an ETL of less than 30 nm to achieve high electron mobility and efficiently extract carriers from the active layer to avoid charge recombination. [13,14] Such thin films need precise process,w hich is not suitable for large-scale production.…”

“…Asuitable ETL should meet some basic requirements for high device efficiency. [12] SnO 2 -based devices typically require an ETL of less than 30 nm to achieve high electron mobility and efficiently extract carriers from the active layer to avoid charge recombination. [13,14] Such thin films need precise process,w hich is not suitable for large-scale production.…”