The electronic structure of β-TeO 2 as wide bandgap p-type oxide semiconductor

DOI: 10.1063/5.0142734

Authors: Jueli Shi (Xiamen University; Shenzhen Research Institute of Xiamen University) , Ziqian Sheng (Xiamen University; Shenzhen Research Institute of Xiamen University) , Ling Zhu (Xiamen University) , Xiangyu Xu (Xiamen University) , Yun Gao (Xiamen University) , Dingliang Tang (Xiamen University) , Kelvin H. L. Zhang (Xiamen University; Shenzhen Research Institute of Xiamen University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Applied Physics Letters , VOL 122

State: Published (Approved)
Published: March 2023
Diamond Proposal Number(s): 24219 , 31681

Abstract: Wide bandgap oxide semiconductors have gained significant attention in the fields from flat panel displays to solar cells, but their uses have been limited by the lack of high mobility p-type oxide semiconductors. Recently, β-phase TeO2 has been identified as a promising p-type oxide semiconductor with exceptional device performance. In this Letter, we report on the electronic structure of β-TeO2 studied by a combination of high-resolution x-ray spectroscopy and hybrid density functional theory calculations. The bulk bandgap of β-TeO2 is determined to be 3.7 eV. Direct comparisons between experimental and computational results demonstrate that the top of a valence band (VB) of β-TeO2 is composed of the hybridized Te 5s, Te 5p, and O 2p states, whereas a conduction band (CB) is dominated by unoccupied Te 5p states. The hybridization between spatially dispersive Te 5s2 states and O 2p orbitals helps us to alleviate the strong localization in the VB, leading to small hole effective mass and high hole mobility in β-TeO2. The Te 5p states provide stabilizing effect to the hybridized Te 5s-O 2p states, which is enabled by structural distortions of a β-TeO2 lattice. The multiple advantages of large bandgap, high hole mobility, two-dimensional structure, and excellent stability make β-TeO2 a highly competitive material for next-generation opto-electronic devices.

Journal Keywords: Hybrid density functional calculations; Thin films; Optoelectronic devices; X-ray photoelectron spectroscopy; X-ray diffraction; Electronic structure; Semiconductors; Oxides; Metal oxides; Electronic band structure

Diamond Keywords: Semiconductors

Subject Areas: Materials, Physics


Instruments: I09-Surface and Interface Structural Analysis

Added On: 12/03/2023 19:45

Discipline Tags:

Surfaces Physics Hard condensed matter - structures Electronics Materials Science interfaces and thin films

Technical Tags:

Spectroscopy X-ray Photoelectron Spectroscopy (XPS) Hard X-ray Photoelectron Spectroscopy (HAXPES)