Single GaAs nanowire based photodetector fabricated by dielectrophoresis

Abstract

Mechanical manipulation of nanowires (NWs) for their integration in electronics is still problematic because of their reduced dimensions, risking to produce mechanical damage to the NW structure and electronic properties during the assembly process. In this regard, contactless NW manipulation based methods using non-uniform electric fields, like dielectrophoresis (DEP) are usually much softer than mechanical methods, offering a less destructive alternative for integrating nanostructures in electronic devices. Here, we report a feasible and reproducible dielectrophoretic method to assemble single GaAs NWs (with radius 35–50 nm, and lengths 3–5 μm) on conductive electrodes layout with assembly yields above 90% per site, and alignment yields of 95%. The electrical characteristics of the dielectrophoretic contact formed between a GaAs NW and conductive electrodes have been measured, observing Schottky barrier like contacts. Our results also show the fast fabrication of diodes with rectifying characteristics due to the formation of a low-resistance contact between the Ga catalytic droplet at the tip of the NW when using Al doped ZnO as electrode. The current-voltage characteristics of a single Ga-terminated GaAs NW measured in dark and under illumination exhibit a strong sensitivity to visible light under forward bias conditions (around two orders of magnitude), mainly produced by a change on the series resistance of the device.

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

“…The detectivity of our photodetector is better than that reported for a GaAsSb NW IR detector (1300 nm), although the responsivity of the GaAsSb NW detector is better [ 34 ]. A photodetector based on a single GaAs nanowire with a responsivity of 1.2 mA·W −1 has been recently reported on a nanowire prepared by chemical beam epitaxy (CBE) with a vapor–liquid–solid (VLS) growth procedure [ 35 ]. This value is by two orders of magnitude lower than the responsivity of our photodetector.…”

Directed Assembly of Nanomaterials for Making Nanoscale Devices and Structures: Mechanisms and Applications

“…Another typical application of the DEP phenomenon is aligning and assembling 1D materials 177 such as carbon nanotubes (CNTs), 178−185 metallic nanowires, 186−188 gallium arsenide (GaAs) nanowires, 189 gallium nitride (GaN) nano-…”

“…Another typical application of the DEP phenomenon is aligning and assembling 1D materials 177 such as carbon nanotubes (CNTs), 178 − 185 metallic nanowires, 186 − 188 gallium arsenide (GaAs) nanowires, 189 gallium nitride (GaN) nanowires, 190 , 191 indium arsenide (InAs) nanowires, 192 silicon nanowires, 193 − 195 manganese dioxide (MnO 2 ) nanowires, 196 , 197 nanofibers, 198 and biofunctionalized nanowires. 199 Unlike zero-dimensional (0D) nanoparticles, 1D materials experience an anisotropic DEP force, depending on their orientation in the electric field.…”

“…(d) Fabrication of GaAs nanowire-based photodetectors using the DEP assembly process. Reprinted with permission under a Creative Commons CC BY 4.0 License from ref ( 189 ). Copyright 2020, IOP Publishing Ltd.…”

“…Fabrication of photodetectors using the directed assembly process has also been demonstrated. 186 , 189 , 437 , 438 García Núñez et al 189 used DEP to fabricate photodetectors from GaAs nanowires ( Figure 19 d). Individual GaAs nanowires 35–50 nm in radius and 3–5 μm in length were assembled between patterned electrodes at a high assembly yield of >90% and alignment yield of >95%.…”