Growth and Optical Properties of Ho Doped n-Type Indium Selenide

Abstract

n-InSe and Ho doped n-InSe (n-InSe:Ho) single crystals were grown by a method which is similar to the direct freezing method. The crystals used in this study were grown in our crystal growth laboratory. The ingots had no cracks and voids on the surface. There was no process to polish and clean the samples because of the natural mirror-like cleavage faces. The X-ray Laue back-reflection method was used to test the crystallinity of the prepared sample. The absorption measurements were carried out in n-InSe:Ho sample in the temperature range from 10 to 320 K. The exciton energies for n = 1 were calculated as 1.315, 1.302, 1.266 and 1.238 eV in n-InSe:Ho at 10, 100, 200 and 280 K, respectively. The exciton energies for n = 2 in n-InSe:Ho are 1.328, 1.322, 1.318 at 10, 60 and 80 K, respectively. The exciton binding energy of n-InSe:Ho was calculated as 17.3 meV. The direct band gaps for n-InSe:Ho are 1.332, 1.313, 1.283 and 1.255 eV at 10, 100, 200, 280 K, respectively.