Optimizing the single-source flash thermal evaporation process of Zn-doped CsPbBr${}_3$ films for enhanced performance in perovskite LEDs

In this study, we employed the flash thermal evaporation method to create thin films of CsPbBr${}_3$ doped with Zn${}^{2+}$ thin film as an emitting layer, aiming to boost the performance of LED devices. ZnBr${}_2$ was added to CsPbBr${}_3$ powders at different concentrations (0%, 5%, 10%, 15%, and 20%), using it as a sole source material for vacuum thermal evaporation. It was found that with the incorporation of 10% Zn${}^{2+}$, the photoluminescence intensity of the film was 2.5 times higher than that of the undoped CsPbBr${}_3$ film. As a result, the LED based on 10%- Zn doped CsPbBr${}_3$ emitter layer shows the highest luminance and current efficiency of up to 5000 cd m${}^{-2}$ and 5.89 cd × A${}^{-1}$, respectively at 4.8 V, which is much higher than that of the device based on CsPbBr${}_3$ (1321 cd m${}^{-2}$ and 0.09 cd × A${}^{-1}$). The findings of this research are anticipated to benefit future perovskite LED studies using single-source thermal evaporation.