Experimental and theoretical investigation of enhanced thermoelectric performance of GaAs1−xNx alloy with Si

In this thesis, the application of un-doped and Si-doped gallium arsenide nitride (GaAs1−xNx) samples grown by Metal Organic Vapor Phase Epitaxy (MOVPE) technique on semi-insulating (SI) and n-type gallium arsenide (GaAs) substrates as a novel thermoelectric material was investigated. Three different types of sample, which are fabricated in a horizontal MOVPE reactor by researcher Mr. Matte BOSI from Council of National Research (CNR) in Italy, have been included in this study. X-Ray Diffraction (XRD) measurements for structural analysis, photoluminescence (PL) measurements for optical properties and Hall effect measurements for electrical results have been performed in Gazi University. The Hall effect measurements were made as a function of temperature. The effects of layer structure and growth conditions of the samples on thermoelectric performance of GaAs1−xNx were demonstrated by obtaining values of the power factor (PF). Results show that Si doping has an affirmative influence on the PF value of GaAs1−xNx when the samples are comprised to each other. It is found that the PF value of Si doped GaAs1−xNx is approximately equal to ten times PF value of un-doped GaAs1−xNx. So that Si-doped GaAs1−xNx might be considered as a promising candidate for thermoelectric energy harvesters.