Vapor-Assisted In Situ Recrystallization for Efficient Tin-Based Perovskite Light-Emitting Diodes.

Zhang, Fang; Min, Hao; Zhang, Ya; Kuang, Zhiyuan; Wang, Jiaqi; Feng, Ziqian; Wen, Kaichuan; Xu, Lei et al. · Adv Mater · 2022

basic_science · Level V

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Abstract

Tin-based perovskites are a promising candidates to replace their toxic lead-based counterparts in optoelectronic applications, such as light-emitting diodes (LEDs). However, the development of tin perovskite LEDs is slow due to the challenge of obtaining high-quality tin perovskite films. Here, a vapor-assisted spin-coating method is developed to achieve high-quality tin perovskites and high-efficiency LEDs. It is revealed that solvent vapor can lead to in situ recrystallization of tin perovskites during the film-formation process, thus significantly improving the crystalline quality with reduced defects. An antioxidant additive is further introduced to suppress the oxidation of Sn<sup>2+</sup> and increase the photoluminescence quantum efficiency up to ≈30%, which is an approximately fourfold enhancement in comparison with that of the control method. As a result, efficient tin perovskite LEDs are achieved with a peak external quantum efficiency of 5.3%, which is among the highest efficiency of lead-free perovskite LEDs.