Interdigital Electrode-Based Quantum Dot Light-Emitting Device Without Carrier Injection/Transport Layers
Alternating current (AC)-driven quantum dot (QD) light-emitting diodes have garnered attention for their unique optoelectronic performance. This work proposes an AC-driven device with an interdigital electrode structure that eliminates carrier injection and transport layers. The device exhibits AC electroluminescence (EL) with distinct frequency responses due to the incorporation of P(VDF-TrFE-CFE). Optical and electrical characteristics were studied under varying applied voltages and driving frequencies. Unlike conventional DC-driven devices where carriers are continuously injected, carriers in this device undergo periodic motion under an AC field, resulting in an optimal driving frequency that maximizes EL intensity. Experimental results reveal an optimal driving frequency of 50 kHz. A carrier transport model is proposed to elucidate the underlying factors contributing to this optimal frequency, and an equivalent circuit model is developed and verified. From a circuit perspective, the EL behavior at various frequencies is analyzed, further confirming the proposed working mechanism. Under high-frequency electric fields, exciton dissociation and reduced carrier accumulation at insulating layer interfaces are identified as primary causes of performance degradation. This work provides guidance for advancing QD-based light-emitting technology.