Unraveling the Hole-Transport-Layer-Manipulated Carrier Transfer Dynamics in Perovskite Light-Emitting Diodes

Charge transfer dynamics is decisive for the performance of perovskite light emitting diodes (PeLEDs), and deep insight into the charge transfer process inside the working device is indispensable. Here, the influence of the hole transport layer on charge transport and recombination processes in PeLEDs is investigated via impedance spectroscopy. The results demonstrate that the rational interfacial energy level alignment can improve the radiative recombination by reducing the leakage current and carrier transport resistance. Shockley–Read–Hall recombination and Auger recombination enlarge the lifetime of carrier transfer in the working devices as determined from the electroluminescence spectrum. Our work provides a distinctive and reliable method to explore the charge transfer property and highlights the importance of interfaces to boost the performance of PeLEDs.