Photoresponse Improvement of InGaAs Nanowire Near-Infrared Photodetectors with Self-Assembled Monolayers

Abstract

InGaAs nanowires (NWs) show tremendous potential as channel materials in the field of near-infrared photoelectric detections. However, the abundance of surface states on InGaAs NWs has limited the photoelectronic properties of the devices, and further performance enhancement can be achieved by manipulating NWs surface state charges. In this work, high-quality InGaAs NWs are synthesized by two-step chemical vapor deposition, and high-performance near-infrared photodetectors are achieved based on the as-grown NWs with a large responsivity of 3.7 × 103 A/W, a superior detectivity of 1.01 × 1011 jones, and an external quantum efficiency of 4.34 × 103% under 1064 nm irradiation. More importantly, self-assembled monolayers are employed for the surface modification of InGaAs NW photodetectors using a simple wet chemistry, in which the inorganic (NH4)2S monolayer enhances the sensitivity of the devices by reducing the response time and the organic 1-octadecanethiol monolayer improves the photoresponse of the devices by raising the photocurrent. This work offers significant reference values to modulate the surface states of ternary and multielement NWs and improving the photoelectric performance of nanoscale broadband photodetectors for next-generation advanced optoelectronic devices.