Influence of drying temperature on morphology of MAPbI$_3$ thin films and the performance of solar cells

TL;DR

This study investigates how drying temperature affects the surface morphology of MAPbI3 thin films prepared via anti-solvent method and how these morphological changes influence the efficiency of perovskite solar cells, achieving a maximum efficiency of 14.4%.

Contribution

It reveals the relationship between drying temperature, film morphology, and solar cell performance, optimizing drying conditions for better efficiency.

Findings

Higher drying temperatures increase grain size and surface roughness.

Optimal drying temperature of 60°C yields the highest solar cell efficiency.

Surface morphology significantly impacts charge recombination and device performance.

Abstract

Photoelectric conversion efficiency of organic-inorganic perovskite solar cells has been rapidly raised and attracted great attention in recent years. The quality of perovskite films is vital for the performance of devices. We used the anti-solvent method to prepare CH$_3$NH$_3$PbI$_3$ thin films by spin coating and dried them at various temperature to transform adduct MAI.PbI$_2$.DMSO into CH$_3$NH$_3$PbI$_3$. We researched in detail on the relationship between surface morphology of MAPbI$_3$ thin films fabricated by the anti-solvent method and various drying temperature. We found that surface roughness and grain size of CH$_3$NH$_3$PbI$_3$ films together increased with increasing drying temperature. The larger grain size could efficiently reduce crystal boundaries which is advantageous for the suppression of photo-induced charge carrier recombination resulting in increase of FF. However, increase of surface roughness resulted in larger contact area at interface which might produce more tarp states and poorer wettability of HTM solution leading in decrease of Jsc. Surface morphology of MAPbI3 layer on the performance of solar cell devices is also an important research issue. By optimizing the drying temperature to 60 oC, the highest efficiency of 14.4% was achieved for the CH3NH3PbI3-based solar cell devices.