Optical properties of MgO thin films grown by laser ablation technique

A. Zawadzka,J. Strzelecki,P. Trzaska,A. Korcala,D. Guichaoua,B. Sahraoui,P. Płóciennik

doi:10.1007/s11082-016-0536-8

Abstract

We have investigated the structural, linear and nonlinear optical properties of high-quality MgO thin films deposited by laser ablation technique on quartz substrates. The deposition process was carried out at various temperatures of the substrates from room temperature to 600 °C in order to investigate these properties of the films and their mutual influence. The structural and morphological properties of the films were investigated by X-ray diffraction. The quality of the films was improved with an increase of the substrate temperature. The linear optical properties of the films were studied by classic and time-resolved photoluminescence spectra in the broad range of the temperature form 13 to 300 K. An innovative time-resolved photoluminescence technique let us precisely measure the decay time in the real time. Results of these measurements reveal a simple exponential decay behavior typical for well oriented crystalline thin films. Presented spectra confirm high structural and linear optical quality of investigated films. The nonlinear optical properties of the films were investigated by third harmonic generation technique. Our results indicated that the substrate temperature slightly affected nonlinear optical properties and the values of third order nonlinear susceptibilities at the 600 °C were found to be smaller relative to RT. All these unusual properties of MgO thin films deposited by laser ablation technique made this material very interesting for the subsequent oriented growth of the other oxide a but also for potential other optical applications.

Highlights

We have investigated the structural, linear and nonlinear optical properties of high-quality Magnesium oxide (MgO) thin films deposited by laser ablation technique on quartz substrates
Our results indicated that the substrate temperature slightly affected nonlinear optical properties and the values of third order nonlinear susceptibilities at the 600 °C were found to be smaller relative to room temperature (RT)
This paper was focused on the growth and optical properties of magnesium oxide (MgO) thin films fabricated by laser ablation process

Summary

Experimental

Time distribution of ablated species inside the plasma plume is very important for understanding the PLD processes and the thin films deposition. The MgO ion–atomic plume was produced by irradiation of the MgO target by the excimer laser beam (Zawadzka et al 2015a; Rumianowski and Płociennik 2006; Zielinski et al 2000). A constant field for time-of-flight (TOF) mass spectrometer was used to investigate the expansion dynamics of the ionic species ejected during ablation process (Zawadzka et al 2015a; Rumianowski and Płociennik 2006). Electrons and uncharged molecules were produced in the laser radiation interaction region at the MgO target inside the vacuum chamber. The computer was used for registering the laser power from the pulse energy meter for each laser shot

Results and discussion

Structural study of MgO thin films

Linear optical properties of the amorphous MgO thin films

Nonlinear optical properties of the MgO thin films

Conclusion