Optical and electrical characterization of InGaAs epitaxial layers

InGaAs alloy is a semiconductor material that is used in detectors operating in the infrared (IR) region by changing the In alloy composition in controlled growth processes by adjusting the band gap to about 0,75eV. The band gap at room temperature corresponds to around 1,65 µm, and it has the potential to be used as an optoelectronic device that radiates around this wavelength. In this work¸ In0,53GaA0,47As alloy with different thickness and carrier concentrations grown on semi-insulating InP by using Metal Organic Vapor Phase Epitaxy (MOVPE) method were studied and energy band gaps, carrier concentrations, carrier mobilities, and temperature dependence of these parameters were determined. The energy band gap of this material, depending on the temperature, in the range of 33 K and 300 K, was investigated using the photoluminescence (PL) method and the temperature dependent carrier concentration and carrier mobility between 77 K and 300 K were determined using Hall effect method. The investigated structures are n-type and since they have different carrier concentrations¸ so the existence of effects such as band gap narrowing or band tail formation in case of different carrier concentration in the band gap were also investigated.