Investigation of Structural, Optical, and Electrical Properties of In‐Doped SnO2 Thin Films Deposited by Spray Pyrolysis

Abstract

In this work, undoped and 1–5 at.% In-doped SnO2-δ films are deposited onto glass substrates at 350 °C by spray pyrolysis technique. The influence of dopant concentration is investigated using X-ray diffraction (XRD), UV-Visible spectroscopy, and Hall Effect measurements using van der Pauw method. X-ray diffraction studies indicate that all films had preferred orientation along (200) plane and are polycrystalline with tetragonal rutile structure. The calculated average crystallite sizes increased after doping. Substitution of In into SnO2-δ thin films can be confirmed by the shifting of the peaks in the XRD patterns. Optical transmittance of the films show high average transparency ∼80–90% in the visible region. Hall measurements show that the conduction type is dependent on In content. For low-doped films (In ≤3 at.%), the films are n-type, while at higher doping concentration the films are p-type. The calculated values of the mean free path are very small compared to the average crystallite sizes calculated using XRD measurements. Therefore, we suggest that ionized and/or neutral impurity scattering are the main scattering mechanisms in these films. The above-mentioned characteristics render these In-doped SnO2 films potential candidates for their use in light-emitting diode and in optoelectronic devices, with the advantage that they are prepared by a simple and economical technique.