Regular Article

Perovskite solar cell with SnO₂ mesoporous thin films as electron transport layer: facile fabrication, investigation of the effects of growth parameters^★

¹ Department of Materials Engineering, Semnan University, Semnan 1911135131, Iran
² Department of Materials and Polymer Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran

^* e-mail: m.abed@semnan.ac.ir
^** e-mail: b.ghasemi@semnan.ac.ir

Received: 17 September 2022
Accepted: 21 November 2022
Published online: 9 January 2023

Abstract

Mesoporous SnO₂ thin films were prepared via a facile sol gel-based method. The effects of two different solvents (ethanol and 1-butanol), different drying conditions (relative humidity (RH) of 34 and 80%), and calcination temperatures (T_C  =  300, 400, and 500 °C) on the structural and surface properties of the layers were investigated. The SnO₂ thin films prepared with butanol exhibited lower thickness, lower surface area, and higher surface macro-roughness. The polarity, viscosity, and steric hindrance of solvents were compared and their effects on the final layer properties were discussed. The results of characterization analyses revealed that thicker and puffier SnO₂ thin films with a higher surface area were obtained under higher humidity. Higher T_C resulted in higher surface macro-roughness, while the highest surface area of 88.2 m²/g was obtained for mild T_C  =  400 °C. Perovskite solar cells (PSCs) were fabricated with different mesoporous SnO₂ thin films and an electron transport layer (ETL). The highest power conversion efficiency of 13.09% was obtained for the PSCs containing SnO₂ thin film prepared with ethanol as solvent, dried under RH = 80%, and calcined at T_C  =  400 °C. The factors describing the best performance were explored and discussed.