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

InGaAsnanowires (NWs) show tremendous potential as channel materialsin the field of near-infrared photoelectric detections. However, theabundance of surface states on InGaAs NWs has limited the photoelectronicproperties of the devices, and further performance enhancement canbe achieved by manipulating NWs surface state charges. In this work,high-quality InGaAs NWs are synthesized by two-step chemical vapordeposition, and high-performance near-infrared photodetectors areachieved based on the as-grown NWs with a large responsivity of 3.7x 10(3) A/W, a superior detectivity of 1.01 x 10(11) jones, and an external quantum efficiency of 4.34 x10(3)% under 1064 nm irradiation. More importantly, self-assembledmonolayers are employed for the surface modification of InGaAs NWphotodetectors using a simple wet chemistry, in which the inorganic(NH4)(2)S monolayer enhances the sensitivity ofthe devices by reducing the response time and the organic 1-octadecanethiolmonolayer improves the photoresponse of the devices by raising thephotocurrent. This work offers significant reference values to modulatethe surface states of ternary and multielement NWs and improving thephotoelectric performance of nanoscale broadband photodetectors fornext-generation advanced optoelectronic devices.

Automated summary

High-quality InGaAs nanowires were synthesized by chemical vapor deposition and their surface was modified using simple wet chemistry. The modified nanowires showed significantly improved photoelectronic properties, with enhanced response time and photocurrent. This study offers important reference values for modulating surface states of ternary and multielement nanowires and improving the performance of nanoscale broadband photodetectors.