Thermally Evaporated CsPbBr3 for Green Perovskite Light-Emitting Diodes: Challenges and Perspectives

Semiconductors based on metal halide perovskites have been extensively studied recently due to their potential as materials for optoelectronic applications. In the realm of cesium-based inorganic perovskite light-emitting diodes (PeLEDs), several aspects are of paramount importance to achieve high photoluminescence (PL) and electroluminescence (EL) of the PeLEDs. The fabrication of CsPbBr₃ via thermal evaporation, employing different ratios and stoichiometries, has demonstrated an efficient PL performance in films at high CsBr concentrations. Interface engineering approaches and defect-passivating additives can promote the growth of uniform and high-quality perovskite films. However, such strategies may lead to device degradation, resulting in low stability. Currently, obtaining defect-free thin films is a crucial prerequisite. From a materials perspective, this critical review article covers the composition of the active layer and its effect on the PL and, from the device, the role of additives in obtaining uniform films, assuring optimal charge transport, and electrical injection to achieve high EL.