UV Photosensing Characteristics of Nanowire-Based GaN/AlN Superlattices

Abstract

We have characterized the photodetection capabilities of single GaN nanowires incorporating 20 periods of AlN/GaN:Ge axial heterostructures enveloped in an AlN shell. Transmission electron microscopy confirms the absence of an additional GaN shell around the heterostructures. In the absence of a surface conduction channel, the incorporation of the heterostructure leads to a decrease of the dark current and an increase of the photosensitivity. A significant dispersion in the magnitude of dark currents for different single nanowires is attributed to the coalescence of nanowires with displaced nanodisks, reducing the effective length of the heterostructure. A larger number of active nanodisks and AlN barriers in the current path results in lower dark current and higher photosensitivity, and improves the sensitivity of the nanowire to variations in the illumination intensity (improved linearity). Additionally, we observe a persistence of the photocurrent, which is attributed to a change of the resistance of the overall structure, particularly the GaN stem and cap sections. In consequence, the time response is rather independent of the dark current.

This document is the unedited Author's version of a Submitted Work that was subsequently accepted for publication in Nano Letters (2016), copyright (C) American Chemical Society after peer review. To access the final edited and published work see http://dx.doi.org/10.1021/acs.nanolett.6b00806

References in corpus (13)

• GaAs/AlGaAs Nanowire Photodetector
• Nanometer Scale Spectral Imaging of Quantum Emitters in Nanowires and Its Correlation to Their Atomically Resolved Structure
• Luminescence associated with stacking faults in GaN
• Direct experimental determination of the spontaneous polarization of GaN
• Monitoring the formation of nanowires by line-of-sight quadrupole mass spectrometry: a comprehensive description of the temporal evolution of GaN nanowire ensembles
• Carrier Confinement in GaN/AlGaN Nanowire Heterostructures for 0 < x <= 1
• Coexistence of quantum-confined Stark effect and localized states in an (In,Ga)N/GaN nanowire heterostructure
• Statistical analysis of the shape of one-dimensional nanostructures: determining the coalescence degree of spontaneously formed GaN nanowires
• Ultrafast photodetection in the quantum wells of single AlGaAs/GaAs-based nanowires
• Investigating the origin of the nonradiative decay of bound excitons in GaN nanowires
• Screening of the quantum-confined Stark effect in AlN/GaN nanowire superlattices by Germanium doping
• Environmental sensitivity of n-i-n and undoped single GaN nanowire photodetectors
• Long-lived excitons in GaN/AlN nanowire heterostructures

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• Performance analysis of photodetectors based on 2D materials and heterostructures
• Nanowire photodetectors based on wurtzite semiconductor heterostructures
• Effect of the nanowire diameter on the linearity of the response of GaN-based heterostructured nanowire photodetectors
• Ultraviolet Photodetectors based on GaN and AlGaN/AlN Nanowire Ensembles: Effects of Planarization with Hydrogen Silsesquioxane and Nanowire Architecture
• Correlated and in-situ electrical transmission electron microscopy studies and related membrane fabrication
• Near- and mid-infrared intersubband absorption in top-down GaN/AlN nano- and micropillars