Due to the better stability and environment-friendly nature, lead-free halide double perovskites are widely explored as promising materials for next-generation photovoltaics and optoelectronics; however, to date, their photoelectric device performance is still not satisfactory. Herein, we report a facile solution-process method to synthesize the recently most popular lead-free halide double perovskite, MA₂AgBiBr₆, and its all-inorganic counterpart, Cs₂AgBiBr₆. The obtained MA₂AgBiBr₆ and Cs₂AgBiBr₆ films exhibit the microplatelet morphology with excellent crystallinity, distinctly contrasting the ones fabricated by the conventional spin-coating method. Once fabricated into simple photodetectors, the Cs₂AgBiBr₆ microplatelet devices yield a respectable responsivity of 245 mA W⁻¹ that is two orders of magnitude larger than that of the spin-coated films. More importantly, the response speed of the Cs₂AgBiBr₆ microplatelets device is as fast as 145 µs, which is higher than most of the values reported in the community of halide double perovskites. When subjected to the thermal stability testing, the Cs₂AgBiBr₆ microplatelet device can maintain its initial performance after heating to 160°C and cooling down to room temperature in the ambient environment. All these results suggest that the facile solution-process method is capable of fabricating high-quality lead-free double perovskites, enabling their advanced device applications.

無鉛雙鈣鈦礦由於具有較好的穩定性和無毒的特點吸引了很多學者的目光, 有希望成為下一代光伏和光電子材料. 然而, 目前其光電器件性能並不理想. 我們報導了一個簡單的溶液法用於製備無機雙鈣鈦礦 Cs₂AgBiBr₆ 和 MA₂AgBiBr₆ 微米片. 與傳統的溶液旋塗法相比, 這種方法得到的 Cs₂AgBiBr₆ 和 MA₂AgBiBr₆ 微米片具有很好的結晶性. 將它們做成光電探測器後, 其響應度達到了 245 mA W⁻¹, 比旋塗法製備的器件高出兩個量級, 且響應時間為 145 μs. 熱穩定性研究表明, 將 Cs₂AgBiBr₆ 器件在空氣中加熱到 160°C 再回到室溫, 其光電響應並沒有受到影響. 這些結果表明, 溶液法製備無鉛雙鈣鈦礦具有更廣闊的應用前景.