Impact of a Mesoporous Titania–Perovskite Interface on the Performance of Hybrid Organic–Inorganic Perovskite Solar Cells

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• 作者：Mojtaba Abdi-Jalebi ; M. Ibrahim Dar ; Aditya Sadhanala ; Satyaprasad P. Senanayak ; Fabrizio Giordano ; Shaik Mohammed Zakeeruddin ; Michael Grätzel ; Richard H. Friend
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2016
• 出版时间：August 18, 2016
• 年：2016
• 卷：7
• 期：16
• 页码：3264-3269
• 全文大小：438K
• 年卷期：0
• ISSN：1948-7185

文摘

We report on the optimization of the interfacial properties of titania in mesoscopic CH₃NH₃PbI₃ solar cells. Modification of the mesoporous TiO₂ film by TiCl₄ treatment substantially reduced the surface traps, as is evident from the sharpness of the absorption edge with a significant reduction in Urbach energy (from 320 to 140 meV) determined from photothermal deflection spectroscopy, and led to an order of magnitude enhancement in the bulk electron mobility and corresponding decrease in the transport activation energy (from 170 to 90 meV) within a device. After optimization of the photoanode–perovskite interface using various sizes of TiO₂ nanoparticles, the best photovoltaic efficiency of 16.3% was achieved with the mesoporous TiO₂ composed of 36 nm sized nanoparticles. The improvement in device performance can be attributed to the enhanced charge collection efficiency that is driven by improved charge transport in the mesoporous TiO₂ layer. Also, the decreased recombination at the TiO₂–perovskite interface and better perovskite coverage play important roles.