Distinct Photocurrent Response of Individual GaAs Nanowires Induced by n-Type Doping

Abstract

The doping-dependent photoconductive properties of individual GaAs nanowires have been studied by conductive atomic force microscopy. Linear responsivity against the bias voltage is observed for moderate n-doped GaAs wires with a Schottky contact under illumination, while that of the undoped ones exhibits a saturated response. The carrier lifetime of a single nanowire can be obtained by simulating the characteristic photoelectric behavior. Consistent with the photoluminescence results, the significant drop of minority hole lifetime, from several hundred to subpicoseconds induced by n-type doping, leads to the distinct photoconductive features. Moreover, by comparing with the photoelectric behavior of AlGaAs shelled nanowires, the equivalent recombination rate of carriers at the surface is assessed to be >1 × 10(12) s(-1) for 2 × 10(17)cm(-3) n-doped bare nanowires, nearly 30 times higher than that of the doping-related bulk effects. This work suggests that intentional doping in nanowires could change the charge status of the surface states and impose significant impact on the electrical and photoelectrical performances of semiconductor nanostructures.

High‐Responsivity Photodetection by a Self‐Catalyzed Phase‐Pure p‐GaAs Nanowire

“…Photodetectors based on III–V semiconductor NWs have been fabricated in different configurations such as core–shell nanostructures, alloys, and heterostructures . Among all III–V NWs, gallium arsenide (GaAs) NWs have gained immense attention for detection application over recent years because of their high light‐to‐electricity conversion efficiency, moderate direct bandgap (1.42 eV), and high compatibility with Si technology, which in turn make them suitable for various outstanding optoelectronic applications like solar cells, photodetectors, p‐n diodes, and field effect transistors …”

Carrier Recombination Dynamics in Sulfur-Doped InP Nanowires

“…40 Band bending due to doping has been reported in p-doped (Zn-doped) InP NWs 42 and n-doped GaAs NWs 40,43 and is used to describe the adsorption and desorption processes of oxygen ions processes in ZnO photodetectors. 44 Here, the band bending model fits our observations.…”

Formation of GaAs/GaSb Core-Shell Heterostructured Nanowires Grown by Molecular-Beam Epitaxy

“…III-V semiconductor nanowires (NWs) have been studied extensively in recent years due to their unique physical properties [1,2] and, in turn, have been used in a wide range of applications, including solar cells [3][4][5], nanolasers [6], infrared detectors [7][8][9], and quantum computing [10,11]. With their growth feature of being free-standing, NWs can withstand much higher lattice mismatch, since the strain at the hetero-interface between two different materials can be elastically relieved easily [12].…”