Coevaporation Stabilizes Tin-Based Perovskites in a Single Sn-Oxidation State.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35998901.
- Also identified by DOI 10.1021/acs.nanolett.2c02204 and PMC identifier 9479155.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Chemically processed methylammonium tin-triiodide (CH<sub>3</sub>NH<sub>3</sub>SnI<sub>3</sub>) films include Sn in different oxidation states, leading to poor stability and low power conversion efficiency of the resulting solar cells (PSCs). The development of absorbers with Sn [2+] only has been identified as one of the critical steps to develop all Sn-based devices. Here, we report on coevaporation of CH<sub>3</sub>NH<sub>3</sub>I and SnI<sub>2</sub> to obtain absorbers with Sn being only in the preferred oxidation state [+2] as confirmed by X-ray photoelectron spectroscopy. The Sn [4+]-free absorbers exhibit smooth highly crystalline surfaces and photoluminescence measurements corroborating their excellent optoelectronic properties. The films show very good stability under heat and light. Photoluminescence quantum yields up to 4 × 10<sup>-3</sup> translate in a quasi Fermi-level splittings exceeding 850 meV under one sun equivalent conditions showing high promise in developing lead-free, high efficiency, and stable PSCs.