Microstructural and optical properties of SnO2 thin films grown on heavily doped n-InP(100) substrates

Abstract

Bright-field transmission electron microscopy (TEM) and high-resolution TEM images and an electron diffraction pattern showed that the SnO2 layers grown on heavily doped n-InP(100) substrates were nanoscale thin films. X-ray photoelectron spectroscopy showed that the positions of the peaks corresponding to the Sn 3d5/2, the Sn 3d3/2, and the O 1s levels for the SnO2 thin film were slightly shifted toward the lower energy side in comparison with those for bulk SnO2. The refractive indices obtained by spectroscopic ellipsometry were above 2.2 around the SnO2 energy gap of the SnO2 thin films. The maximum intensity of the optical transmittance for the SnO2 nanoscale thin film with 3939 Å thickness was above 90%.