Efficient Charge Injection for Perovskite Light‐Emitting Transistor

Abstract Metal halide perovskite semiconductors have demonstrated remarkable performance in light‐emitting‐diode applications in recent years. However, their potential application in other emerging optoelectronic devices, such as light‐emitting field‐effect transistors (LEFETs) is impeded by poor luminous efficiency due to inefficient charge injection. Here, an n‐type MgZnInO (MIZO) as the channel layer is synthesized to achieve efficient electron injection in perovskite LEFETs. These findings indicate that the incorporation of Mg not only suppresses the generation of oxygen vacancies but also optimizes the energy level alignment. These synergistic effects reduce non‐radiative recombination and improve interfacial charge transport. Consequently, the MIZO‐based perovskite LEFETs exhibit an improvement in threshold voltage, subthreshold swing, and field‐effect mobility. The electroluminescence performance shows a peak external quantum efficiency (EQE) of 1.97% with a maximum brightness of 2.1 × 10 4 cd m −2 , accompanied by low‐efficiency roll‐off (an EQE of 1.88% at the current density of 810 mA cm −2 ). To the best of the author's knowledge, this represents the best luminous efficiency reported for perovskite LEFETs to date.