Properties of N-Type GaN Thin Film with Si-Ti Codoping on a Glass Substrate

Wei-Sheng Liu,Cheng-Ting Tsai,Yu-Lin Chang,Hsing-Chun Kuo,Chun-Yuan Tan

doi:10.3390/cryst10070582

Abstract

In this study, n-type gallium nitride (GaN) films were fabricated by a silicon–titanium (Si-Ti) codoping sputtering technique with a zinc oxide (ZnO) buffer layer on amorphous glass substrates with different post-growth annealing temperatures for optimizing the GaN crystal quality. Si-Ti-codoped n-type GaN films that were thermally annealed at 400 °C had a low thin-film resistivity of 2.6 × 10−1 Ω-cm and a high electron concentration of 6.65 × 1019 cm−3, as determined through Hall measurement. X-ray diffraction (XRD) results revealed a high (002) XRD intensity with a narrow spectral line and a full width at half maximum (FWHM) value that indicated the superior crystal growth of a hexagonal structure of the GaN thin films. In addition, photoluminescence measurement results demonstrated a near-band-edge emission at 365 nm, indicating the crystal growth of GaN thin films on glass substrates. The Burstein–Moss effect was observed in the Tauc plot results, indicating that the Fermi level inside the conduction band moves upward and thus improves the n-type properties of the GaN thin film. X-ray photoelectron spectroscopy measurement results revealed that all atoms doped into the GaN film are present and that both Si and Ti atoms bond with N atoms.

Highlights

In recent decades, semiconductor materials based on III–V compounds are useful or even essential for many commercial technologies as well as for cutting-edge electronic and optoelectronic devices such as high-electron-mobility transistors, heterostructure bipolar transistors, diode lasers, and light-emitting diodes (LEDs) [1]
2020, 10, 4 ofthe sputtering-deposited gallium nitride (GaN) thin films preferentially grow with a c-axis orientation and that the crystal quality of the GaN thin films was significantly improved by thermal annealing process
An ultraviolet–visible spectrophotometer was employed to study the optical transmittance of distortion of the crystal lattice of thin films after

Summary

Introduction

Semiconductor materials based on III–V compounds are useful or even essential for many commercial technologies as well as for cutting-edge electronic and optoelectronic devices such as high-electron-mobility transistors, heterostructure bipolar transistors, diode lasers, and light-emitting diodes (LEDs) [1]. III–V nitride-related compound materials are suitable for application in optoelectronic devices with large energy bandgaps. The direct energy bandgaps of nitride-related materials can be widely modulated by incorporating group-III elements to form. For the versatile designs on the optoelectronic devices, the narrow and wide band-gap organic materials are explored and could be combined with the nitride-related materials forming the advantageous applications with superior device performances [3,4].

Methods

Results

Conclusion