Electronic structures and optical properties of sulfur-passivated InAs nanowires by first-principles study

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

“…31 Gong et al investigate the passivation mechanism and photoelectronic properties of InAs NWs after surface sulfur passivation by first-principles, and the density of states near the Fermi level increases, which enhances the conductivity and significantly improves photoconductivity of InAs NWs. 32 However, there have been few reports investigating the surface modification effect on the photoresponsivity of ternary InGaAs NW photodetectors with selfassembled monolayers (SAMs) up to now, and it is of great practical importance to enhance the photosensing performance of ternary and multielement NW based room-temperature optoelectronic devices.…”

“…Surface defect states of NWs can trap photogenerated carriers and trigger Fermi energy level pinning, which are the main reasons for the performance degradation of the NW-based photodetectors. − For semiconductor optoelectronic devices, the abundant surface states also usually generate large dark currents and cause low luminous efficiency. − In order to eliminate the adverse effects of surface states on optoelectronic devices, plenty of works have been reported to solve the problem, and the surface modification method with good stability, low cost, and controllable operation is commonly employed to modulate the surface states. − For instance, Zhang et al report a sulfur-passivation GaSb NWs photodetector with a thin passivation layer formed on the NW surface to prevent the surface oxidation, which presents a lower dark current and a large responsivity of 9.39 × 10 2 A/W under 1.55 μm incident light . Gong et al investigate the passivation mechanism and photoelectronic properties of InAs NWs after surface sulfur passivation by first-principles, and the density of states near the Fermi level increases, which enhances the conductivity and significantly improves photoconductivity of InAs NWs . However, there have been few reports investigating the surface modification effect on the photoresponsivity of ternary InGaAs NW photodetectors with self-assembled monolayers (SAMs) up to now, and it is of great practical importance to enhance the photosensing performance of ternary and multielement NW based room-temperature optoelectronic devices.…”