Influence of surface termination on electronic configurations at FASnI3/C60 interfaces

Abstract

Ever since organic-inorganic halide perovskites have been employed in electronics and optoelectronics, their unique and excellent photophysical and electrical properties[1–3] have guaranteed their versatile applications in solar cells, LEDs, lasers, photodetectors and beyond[4,5]. Sn-based perovskites along with their surface and interface functionalization after assembling with charge transport layers (CTLs) are considered promising ways to achieve a win-win between environmental friendliness and cell performance [6–10]. In view of the sophisticated chemical and physical properties of Sn-based perovskites, the theoretical calculation based on density functional theory (DFT) has been employed to feasibly and flexibly model the interplay between absorbers and CTLs. In order to understand the fundamental physico-chemical mechanisms of that interplay, the influence of surface termination on structural and electronic properties at FASnI3/C60 (as ETL) interfaces, in particular, the dependence of vacuum level (and by that work function) within surface alone and interface integrated frameworks, thereupon constructing the heterostructure energy level alignment, has been investigated thoroughly. The resulting type-II heterostructures coupled with the increased surface dipole moments and charge carrier mobilities tell an effective charge transport from FASnI3 to C60. Our findings contribute to discovering other promising alternatives as ETLs for lead-free perovskites in the light of surface and interface engineering. This DROP-IT project1 has received funding from the European Union's Horizon 2020 research and innovation Program under the grant agreement No 862656. The information and views set out in the abstracts and presentations are those of the authors and do not necessarily reflect the official opinion of the European Union. Neither the European Union institutions and bodies nor any person acting on their behalf may be held responsible for the use which may be made of the information contained herein. References: 1. ...