One-step synthesis of p-type GaSe nanoribbons and their excellent performance in photodetectors and phototransistors

Abstract

High quality p-type GaSe nanoribbons were synthesized through a one-step thermal deposition process and their optoelectronic characteristics and device applications have been systematically explored. The steady-state CL study reveals the presence of two emission bands and the trap relevant emission at 710 nm is more intense at low temperatures. The GaSe nanoribbon-based photodetectors reflect an excellent spectral responsivity (R_λ) of 31.1 A W⁻¹, external quantum efficiency (EQE) of 11 046% and a detectivity (D*) of 3.29 × 10¹⁰ Jones. In addition, under illumination, the phototransistors have shown quadrupled mobility up to 0.12 cm² V⁻¹ s⁻¹ in comparison with the value (0.03 cm² V⁻¹ s⁻¹) measured in darkness, attributed to a joint effect of increased photo-generated carriers and the reduced Schottky barrier. The success in one-step synthesis of high quality p-type GaSe nanoribbons and the detailed exploration of the optoelectronic properties strongly support their future practical applications.