Film Formation and Characterization of Undoped ZnO on M-plane Sapphire by Mist Chemical Vapour Deposition (Mist-CVD) with Different Carrier Gas Flow Rates

Hla Myo Tun

doi:10.11648/j.sr.20150306.16

Abstract

ZnO thin films were deposited on sapphire substrate by mist chemical vapor deposition (mist-CVD) with different flow rate of carrier gas. This is a simple and low cost method for large-area deposition system. In this experiment, zinc chloride solution was used as sources, and the crystal growth was achieved at the growth temperature of 600°C and various flow rates of Nitrogen gas. The X-ray diffraction (XRD) spectrum was performed, and the photoluminescence spectra proved near-band-edge emission and strong deep-level emissions. In this work, we obtained the optimum condition for crystal growth of ZnO on m-plane sapphire, where XRD θ-2θ single peak at m-plane ZnO.

Highlights

In recent times, II-VI semiconductor materials have been of great interest due to application for luminescence and ultraviolet (UV) optical devices such as light emitting diodes (LEDs) and laser diodes (LDs) [1]
Zinc Oxide (ZnO) proves enormous assure for applications in blue/UV light emitters and photodetectors, over and above transparent electronics, chemical sensors, spintronics, and varistors. Various techniques, such as magnetron sputtering, reactive evaporation, pulse laser deposition (PLD), metaorganic chemical vapor deposition (MOCVD), molecular bean epitaxy (MBE), spray pyrolysis, and sol-gel can be useful for ZnO thin films deposition [2]
A 60ml of zinc chloride solution is ultrasonically atomized to form mist particles of the solution, and the particles are afterward transferred by a carrier gas of nitrogen onto the heat sapphire substrate, forming ZnO film by pyrolysis and chemical reactions

Summary

Introduction

II-VI semiconductor materials have been of great interest due to application for luminescence and ultraviolet (UV) optical devices such as light emitting diodes (LEDs) and laser diodes (LDs) [1]. ZnO (as a group-II oxide) proves enormous assure for applications in blue/UV light emitters and photodetectors, over and above transparent electronics, chemical sensors, spintronics, and varistors Various techniques, such as magnetron sputtering, reactive evaporation, pulse laser deposition (PLD), metaorganic chemical vapor deposition (MOCVD), molecular bean epitaxy (MBE), spray pyrolysis, and sol-gel can be useful for ZnO thin films deposition [2]. We have developed a mist-CVD method as a promising technique that allows superior controllability in film deposition at low cost with an uncomplicated system and low energy consumption [3] In this method, a 60ml of zinc chloride (zinc compound) solution is ultrasonically atomized to form mist particles of the solution, and the particles are afterward transferred by a carrier gas of nitrogen onto the heat sapphire substrate, forming ZnO film by pyrolysis and chemical reactions. It is confirmed that ZnO films have single orientation of crystal

Experiment

Results and Discussions

Conclusion