Optical properties of SnO₂ thin films prepared by pulsed laser deposition technique

Abstract

Tin dioxide (SnO₂) thin-film has been deposited on a glass substrate by pulsed laser deposition technique under different deposition parameters. The effects of varying the parameters of Q-switched Nd-YAG laser such as laser power, frequency, and laser pulse repetition are studied by examining the optical properties. The pulsed laser-deposited SnO₂ films were investigated under both vacuum and an argon background pressure of 10⁻³ mbar. The optical properties result shows a considerable shift in the optical spectra. The absorption edge in the absorption spectrum at high laser repetition (200 pulses per second) shifts to a higher wavelength region after pumping the argon gas. This indicates pumping the argon gas to the vacuum increasing the absorption of the film. In addition, the transmittance of the films starts at a higher wavelength when pumping argon gas. Increasing the pressure by pumping the argon might influence the film deposition and then might increase the absorption. It also indicates the start of transmittance at a lower energy in the absence of argon gas. The reflectance reduces slowly with increasing the wavelength after pumping the argon gas. This might be attributed to the increase in the vacuum pressure which affects the speediness of the film absorption.