<i>β</i>-Ga<sub>2</sub>O<sub>3</sub> nanowires: controlled growth, characterization, and deep-ultraviolet photodetection application
Wei Ruan, Zhengyuan Wu, Jian Liu, Jing Chen, Yabing Shan, Pengyu Song, Zhuoxun Jiang, Ran Liu, Guoqi Zhang, Zhilai Fang
Abstract
Abstract We investigate the growth of ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mn>2</mml:mn> <mml:mo>ˉ</mml:mo> </mml:mover> <mml:mn>01</mml:mn> </mml:math> ) β -Ga 2 O 3 nanowires with a GaN seed crystal in detail. Growth of ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mn>2</mml:mn> <mml:mo>ˉ</mml:mo> </mml:mover> <mml:mn>01</mml:mn> </mml:math> ) β -Ga 2 O 3 nanowires starts with the formation of (001) Ga(II)–O chains of octahedral Ga 2 O 6 structures, indicating the initial formation of ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mn>2</mml:mn> <mml:mo>ˉ</mml:mo> </mml:mover> <mml:mn>01</mml:mn> </mml:math> ) and (001) atomic facets of β -Ga 2 O 3 nanowires. Subsequent growth of Ga 2 O 3 leads to the formation of (100) Ga(I)–O chains and energetically stable (100) and (010) sidewalls and octahedral Ga 2 O 6 structures in the β -Ga 2 O 3 nanowires. Energetically stable tetrahedral GaO 4 structures are eventually formed in the β -Ga 2 O 3 nanowires. High-quality N-doped ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mn>2</mml:mn> <mml:mo>ˉ</mml:mo> </mml:mover> <mml:mn>01</mml:mn> </mml:math> ) β -Ga 2 O 3 nanowires are synthesized and growth kinetics is clarified. The β -Ga 2 O 3 nanowires deep-ultraviolet photodetectors show superior performance with high photoresponsivity (3.5 × 10 3 A W −1 ) and detectivity (9.6 × 10 15 Jones) at −10 V bias.