p-type doping of GaAs nanowires using carbon

Abstract

We report on the electrical properties of Au-catalyzed C-doped GaAs nanowires (NWs) grown by metal organic vapor phase epitaxy. Transport measurements were carried out using a tungsten nanoprobe inside a scanning electron microscope by contacting to the Au catalyst particle of individual nanowires. The doping level could be varied from approximately (4 ± 1) × 1016 cm−3 to (1.0 ± 0.3) × 1019 cm−3 by varying the molar flow of the gas phase carbon precursor, as well as the group V to group III precursor ratio. It was found that the current transport mechanism switches from generation-recombination to tunnelling field emission by increasing the doping level to 1 × 1019 cm−3. Based on a diameter-dependent analysis of the apparent resistivity of the C-doped NWs, we propose that C incorporates into GaAs NWs through the triple boundary at the Au/NW interface. The p-type conductivity of the C-doped NWs was inferred by observing a rectification at negative bias (applied to the Au electrode) and confirmed by back-gating measurements performed on field effect transistor devices.

Surface depletion effects in semiconducting nanowires having a non-uniform radial doping profile

“…It can be seen that small-diameter undoped NWs are expected to be completely depleted, even without applying voltage; a reasonable expectation is that low-doped NWs will conduct current in a space charged limited mode, as has been the case in some reports. 12,13 Furthermore, the results suggest a sharp transition from fully depleted to degenerate semiconductor for thin uniformly doped NWs (10 18 to 5 Â 10 18 in Fig. 2(a)).…”

III–V Semiconductor Single Nanowire Solar Cells: A Review

“…Doping is essential for p-n junction based solar cells. In order to grow doped nanowires, Si, [15,59,60] Te, [61,62] Se [63,64] and Sn [65] have been investigated as donors for n-type doping and Zn, [15,64,66] Be [60,62] and C [67] as acceptors for p-doping in III-V nanowires. Si has been used as both acceptors and donors in GaAs due to its amphoteric nature.…”

Review on photonic properties of nanowires for photovoltaics [Invited]

“…Following this report, both n-and p-doped bulk GaAs and InP nanowires were grown. Si, Te and Sn were investigated as donors [66][67][68][69][70][71][72][73] and Zn, Be and C were investigated as acceptors for doping bulk GaAs and InP nanowires [69][70][71][72][73][74][75][76][77][78][79]. The amphoteric nature of Si has enabled its use as an acceptor as well in GaAs [80][81][82].…”