State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering; International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, 310027, China.
Nanoscale. 2023 Apr 13;15(15):6954-6959. doi: 10.1039/d3nr00177f.
The toxicity of lead presents a critical challenge for the application of perovskite optoelectronics. Lead-free perovskite solar cells were achieved with formamidinium tin iodide (FASnI) perovskites, exhibiting decent power-conversion efficiencies (PCEs) of up to 14%, with >98% of the initial PCE retained after 3000 h of storage. However, when employed in light-emitting applications, FASnI-based perovskite LEDs (PeLEDs) show limited stability, with lifetimes of up to 0.25 h at 10 mA cm. Here, we improve the stability of FASnI-based PeLEDs through the inclusion of a two-dimensional precursor phenethylamine iodide (PEAI), allowing controlled crystallization of the mixed-dimensional perovskite emitters. The density of defects is found to be reduced, accompanied by the suppression of oxidation from Sn to Sn. Using an optimized perovskite composition, we achieve an EQE of 1.5% (a ∼10-fold improvement over the control devices), a maximum radiance of 145 W sr m, and a record-long lifetime of 10.3 h at 100 mA cm for FASnI-based PeLEDs. Our results illuminate an alternative path toward lead-free PeLED applications.
铅的毒性对钙钛矿光电应用提出了重大挑战。采用甲脒碘化锡（FASnI）钙钛矿实现了无铅钙钛矿太阳能电池，其功率转换效率（PCE）高达 14%，经过 3000 小时的储存后，初始 PCE 的保留率超过 98%。然而，在用于发光应用时，基于 FASnI 的钙钛矿发光二极管（PeLED）的稳定性有限，在 10 mA cm 的电流密度下，寿命最长可达 0.25 小时。在这里，我们通过引入二维前驱体苯乙胺碘化物（PEAI）来提高基于 FASnI 的 PeLED 的稳定性，从而可以控制混合维钙钛矿发射器的结晶。发现缺陷密度降低，同时抑制了 Sn 到 Sn 的氧化。使用优化的钙钛矿组成，我们实现了 1.5%的 EQE（比对照器件提高了约 10 倍）、145 W sr m 的最大辐射亮度和 10.3 小时的记录长寿命在 100 mA cm 的 FASnI 基 PeLED 下。我们的结果为无铅 PeLED 应用开辟了一条替代途径。
