Effects of Substrate Temperature on Optical, Structural, and Surface Properties of Metal–Organic Vapor Phase Epitaxy-Grown MgZnO Films
Jiamin Liu,
Deng Xie,
Zhe Chuan Feng,
Manika Tun Nafisa,
Lingyu Wan,
Zhi-Ren Qiu,
Dong-Sing Wuu,
Chuanwei Zhang,
Jeffrey Yiin,
Hao-Hsiung Lin,
Weijie Lu,
Benjamin Klein,
Ian T. Ferguson,
Shiyuan Liu
Affiliations
Jiamin Liu
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
Deng Xie
School of Electronic & Electrical Engineering and Physics, Fujian University of Technology, Fuzhou 350000, China
Zhe Chuan Feng
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
Manika Tun Nafisa
Southern Polytechnic College of Engineering and Engineering Technology, Kennesaw University, Marietta, GA 30060, USA
Lingyu Wan
Center on Nano-Energy Research, Guangxi Key Laboratory for the Relativistic Astrophysics, Institute of Science and Technology for Carbon Peak & Neutrality, School of Physical Science & Technology, Guangxi University, Nanning 530004, China
Zhi-Ren Qiu
State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-sen University, Guangzhou 510275, China
Dong-Sing Wuu
Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Puli, Nantou 54561, Taiwan
Chuanwei Zhang
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
Jeffrey Yiin
Southern Polytechnic College of Engineering and Engineering Technology, Kennesaw University, Marietta, GA 30060, USA
Hao-Hsiung Lin
Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
Weijie Lu
Hexagonal Scientific Laboratory, LLC, Dayton, OH 45459, USA
Benjamin Klein
Southern Polytechnic College of Engineering and Engineering Technology, Kennesaw University, Marietta, GA 30060, USA
Ian T. Ferguson
Southern Polytechnic College of Engineering and Engineering Technology, Kennesaw University, Marietta, GA 30060, USA
Shiyuan Liu
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
MgZnO possesses a tunable bandgap and can be prepared at relatively low temperatures, making it suitable for developing optoelectronic devices. MgxZn1−xO (x~0.1) films were grown on sapphire by metal–organic vapor phase epitaxy under different substrate-growth temperatures Ts of 350–650 °C and studied by multiple characterization technologies like X-ray diffraction (XRD), spectroscopic ellipsometry (SE), Raman scattering, extended X-ray absorption fine structure (EXAFS), and first-principle calculations. The effects of Ts on the optical, structural, and surface properties of the Mg0.1Zn0.9O films were studied penetratively. An XRD peak of nearly 35° was produced from Mg0.1Zn0.9O (0002) diffraction, while a weak peak of ~36.5° indicated MgO phase separation. SE measurements and analysis determined the energy bandgaps in the 3.29–3.91 eV range, obeying a monotonically decreasing law with increasing Ts. The theoretical bandgap of 3.347 eV, consistent with the SE-reported value, demonstrated the reliability of the SE measurement. Temperature-dependent UV-excitation Raman scattering revealed 1LO phonon splitting and temperature dependency. Zn-O and Zn-Zn atomic bonding lengths were deduced from EXAFS. It was revealed that the surface Mg amount increased with the increase in Ts. These comprehensive studies provide valuable references for Mg0.1Zn0.9O and other advanced materials.
