Low-voltage RGB perovskite light-emitting transistors with magnetron sputtered Ta2O5 high-k dielectric layer

Abstract

Perovskite light-emitting transistors (PeLETs) represent an emerging class of optoelectronic devices that integrate the exceptional light-emission capabilities of perovskite light-emitting diodes (PeLEDs) with the efficient charge transport properties of field-effect transistors (FETs). This integration facilitates simplified fabrication, enhanced current densities, and stable charge mobility, making PeLETs highly promising for advanced display applications. Low-voltage operation and full-color emission are the primary challenges in achieving high-performance PeLETs. In this work, a PeLET structure that operates at 5 V is designed using a magnetron-sputtered Ta₂O₅ high-k dielectric layer. The influence of the hole transport layer's energy level structure and mobility on the performance of the light-emitting transistor is investigated. By tuning the perovskite bandgap, the PeLETs with emission in the red, green, and blue spectral regions have been achieved. The optimized red-, green-, and blue-emitting PeLETs exhibit charge carrier mobilities of 0.41 cm²V⁻¹s⁻¹, 1.00 cm²V⁻¹s⁻¹, and 0.51 cm²V⁻¹s⁻¹, with corresponding threshold voltages of 0.27 V, 0.64 V, and 0.46 V, respectively. This work advances the development of PeLETs by demonstrating a multilayer device architecture that enhances charge carrier dynamics and expands emission tunability. These findings provide a promising path toward low-voltage PeLETs for next-generation display technologies.