The influence of the mesoporous TiO2 scaffold on the performance of methyl ammonium lead iodide (MAPI) perovskite solar cells: charge injection, charge recombination and solar cell efficiency relationship

Abstract

Methyl Ammonium Lead Iodide (MAPI) perovskite solar cells have achieved over 20% light-to-energy conversion efficiency with the use of a thin mesoporous layer of TiO₂ as a scaffold for the MAPI. Although other solar cell configurations have also been reported, so far only those containing mesoporous TiO₂ (mpTiO₂) have achieved such performance. Herein we describe an exhaustive study of the effects, on the MAPI solar cell performance, of different synthetic routes to achieve nanocrystalline TiO₂ nanoparticles that are used to fabricate the mpTiO₂ layer. Furthermore, we also measured the interfacial charge transfer dynamics to elucidate the device function–charge recombination kinetics relationship in the different types of synthesised mpTiO₂. Our results show that the choice of the chemical properties of the mpTiO₂ layer is of utmost importance to achieve high solar-to-energy conversion efficiencies with remarkable effects on the measured charge carrier recombination kinetics.