Enhanced light-emitting transistors utilizing multi-dimensional CsPbBr3 perovskite films and PVP-modified ZTO semiconductor layers†

Light-emitting transistors (LETs) uniquely combine the electroluminescent features of LEDs with the switching capabilities of field-effect transistors, offering promising applications in advanced display technology, lighting, electrically pumped lasers, and optical communication systems. This study reports on the fabrication and performance of perovskite light-emitting transistors (PeLETs) using solution-processed CsPbBr₃ thin films, enhanced with phenethylammonium bromide (PEABr) and polyethylene oxide (PEO) to create a multi-dimensional mixed phase with a quantum well structure, characterized by a reduced presence of low-dimensional phases and an increased proportion of high-dimensional phases, thereby enhancing exciton recombination efficiency. The incorporation of high-mobility zinc tin oxide (ZTO) films as channel and electron transport layers is investigated. Direct contact between the perovskite and ZTO layers initially leads to an increased off-state current and degraded electrical characteristics of ZTO field-effect transistors (FETs). However, introducing polyvinylpyrrolidone (PVP) as a modification layer significantly improves these characteristics, resulting in a more uniform electric field distribution and consistent surface emission under coplanar electrodes. The optimized PeLET demonstrates mobility of 0.73 cm² V⁻¹ s⁻¹ and an on–off ratio exceeding 10⁵. High-purity green light emission at 514 nm with a narrow full-width at half-maximum (FWHM) of 19.97 nm is achieved, showcasing the potential of PeLETs in various optoelectronic applications.