Effective prediction of SnO2 conduction band edge potential: The key role of surface oxygen vacancies

Abstract

Several theoretical studies at different levels of theory have attempted to calculate the absolute position of the SnO₂ conduction band, whose knowledge is key for its effective application in optoelectronic devices such us, for example, perovskite solar cells. However, the predicted band edges fall outside the experimentally measured range. In this work, we introduce a computational scheme designed to calculate the conduction band minimum values of SnO₂, yielding results aligned with experiments. Our analysis points out the fundamental role of encompassing surface oxygen vacancies to properly describe the electronic profile of this material. We explore the impact of both bridge and in-plane oxygen vacancy defects on the structural and electronic properties of SnO₂, explaining from an atomistic perspective the experimental observables. The results underscore the importance of simulating both types of defects to accurately predict SnO₂ features and provide new fundamental insights that can guide future studies concerning design and optimization of SnO₂-based materials and functional interfaces.