Preparation and Properties of InS Single Crystals

Abstract

We report the preparation and properties of single crystals of the III-VI compound semiconductor InS. Using the solution-growth method from In melt we have prepared single crystals of InS large enough to perform some electrical and optical measurements. The electrical measurements reveal that resistivity parallel to the c-axis of InS is 10∼100 times larger than that perpendicular to the axis. Also, the carrier concentration of as-grown crystals indicating always n-type conduction is more than 1018 cm-3 and the Hall mobility is about 50 cm2/V · sec at room temperature. The experimental data of optical absorption, electroreflectance and photoresponse at the Au-InS Schottky barrier show that the indirect band gap is at 1.90 eV and the direct gap at 2.44 eV at room temperature. The electroreflectance data also reveal structure associated with some higher interband critical points in the energy region from 2.5 to 4.0 eV.