Structural and electrical properties of boron doped InSe single crystals

Abstract

Structural and electrical properties of undoped, 0.1%, 0.5% and 1.8% boron doped InSe single crystals grown by modified Bridgman method have been studied by using XRD, Raman and I-V measurements. XRD spectra reveal that undoped and boron doped crystals investigated have hexagonal structure with lattice parameters a = 4.005 angstrom, c = 16.640 angstrom and z = 4, belonging to the P63/mmc space group. The strongest peak in the XRD patterns is due to the reflection from the (004) plane indicating that these crystals grew with a preferred orientation. Raman spectra show phonon bands in the 400-450 cm(-1) wavenumber range characteristics of InSe single crystals. Temperature dependence of conductivity of undoped and boron doped InSe single crystals show three different mechanisms discerned as extended state conductivity, conduction in band tail and conduction in localized sites. It is observed that electrical conductivity increases while activation energy decreases with increasing boron concentration.