Improved Optoelectronic Properties of Rapid Thermally Annealed Dilute Nitride GaInNAs Photodetectors

Abstract

We investigate the optical and electrical characteristics of GaInNAs/GaAs long-wavelength photodiodes grown under varying conditions by molecular beam epitaxy and subjected to postgrowth rapid thermal annealing (RTA) at a series of temperatures. It is found that the device performance of the nonoptimally grown GaInNAs p + -i-n + structures, with nominal compositions of 10% In and 3.8% N, can be improved significantly by the RTA treatment to match that of optimally grown structures. The optimally annealed devices exhibit overall improvement in optical and electrical characteristics, including increased photoluminescence brightness, reduced density of deep-level traps, reduced series resistance resulting from the GaAs/GaInNAs heterointerface, lower dark current, and significantly lower background doping density, all of which can be attributed to the reduced structural disorder in the GaInNAs alloy.

GaAs1−xBix/GaNyAs1−y type-II quantum wells: novel strain-balanced heterostructures for GaAs-based near- and mid-infrared photonics

“…Indeed, as is generally the case for dilute bismide and nitride materials, the epitaxial growth is relatively immature in comparison to more conventional semiconductor alloys and, hence, optimisation of the growth is required to improve the material quality and optical efficiency. In particular, the presence of short-range alloy disorder, associated with Bi and N clustering, has important consequences for the optical properties, giving rise, for example, to extended Urbach (low-energy) tails in measured PL spectra for GaAs 1− x Bi x and (In)GaN y As 1− y alloys and heterostructures 51 52 53 . The overall character of the measured PL spectrum, which lacks a pronounced high-energy tail as might be expected for a QW heterostructure, is attributed to contributions to the measured PL from localised states lying below the fundamental ( e 1- hh 1) band-to-band transition in energy 54 55 .…”

Experimental study of the effect of local atomic ordering on the energy band gap of melt grown InGaAsN alloys

“…The epitaxial growth under extreme nonequilibrium conditions, such as molecular beam epitaxy (MBE) and metalo-organic chemical beam deposition (MOCVD), favours the formation of various defects responsible for many of the anomalous optical and transport properties of dilute nitride alloys [7][8][9][10]. In order to reduce defect densities and obtain more ordered alloys, additional annealing is performed [11][12][13]. During annealing at thermal equilibrium conditions a short-range ordered structure is partially formed due to increasing number of N-In nearest neighbours over the random configuration.…”

Enhancement of photocurrent in epitaxial lift-off thin-film GaInNAsSb solar cells due to light-confinement structure

“…For the calculation, first, ellipsometry analysis for a separated grown GaInNAsSb film sample was performed to extract the refractive (n) and extinction (k) indices. The effect of the Urbach tail is commonly observed in compound materials, [23][24][25] and fitting with the unfiltered EQE spectrum shows that it cannot be neglected in the calculation. However, the feature of the Urbach tail was not apparent in the extracted k spectrum, which is because the resolution of lower limit in our ellipsometry measurement was not high enough.…”