Direct determination of band-gap renormalization in degenerately doped ultrawide band gap ?- Ga2 O3 semiconductor

Zhang，Jiaye1,2; Willis，Joe3,4,5; Yang，Zhenni1; Sheng，Ziqian1; Wang，Lai Sen6; Lee，Tien Lin5; Chen，Lang2; Scanlon，David O.3,4; Zhang，Kelvin H.L.1

2022-11-15

10.1103/PhysRevB.106.205305

Physical Review B   Impact Factor & Quartile

2469-9950

2469-9969

Ga2O3 is emerging as a promising wide band-gap semiconductor for high-power electronics and deep ultraviolet optoelectronics. It is highly desirable to dope it with controllable carrier concentrations for different device applications. This work reports a combined photoemission spectroscopy and theoretical calculation study on the electronic structure of Si doped Ga2O3 films with carrier concentration varying from 4.6×1018cm-3 to 2.6×1020cm-3. Hard x-ray photoelectron spectroscopy was used to directly measure the widening of the band gap as a result of occupation of conduction band and band-gap renormalization associated with many-body interactions. A large band-gap renormalization of 0.3 eV was directly observed in heavily doped Ga2O3. Supplemented with hybrid density functional theory calculations, we demonstrated that the band-gap renormalization results from the decrease in energy of the conduction band edge driven by the mutual electrostatic interaction between added electrons. Moreover, our work reveals that Si is a superior dopant over Ge and Sn, because Si3s forms a resonant donor state above the conduction band minimum, leaving the host conduction band mostly unperturbed and a high mobility is maintained though the doping level is high. Insights of the present work have significant implications in doping optimization of Ga2O3 and realization of optoelectronic devices.

SCI

English

Others

National Key Research and Development Program of China[2022YFB3605501] ; National Natural Science Foundation of China["22275154","51972160","51771157"] ; Science and Technology Research Items of Shenzhen[JCYJ20180504165650580] ; EPSRC Centre for Doctoral Training in Molecular Modelling and Materials Science[EP/L015862/1] ; EPSRC["EP/N01572X/1","EP/L000202","EP/R029431","EP/T022213","EP/P020194/1","EP/T022213/1"]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:000893198000001

AMER PHYSICAL SOC

2-s2.0-85142809769

Scopus

1.State Key Laboratory of Physical Chemistry of Solid Surfaces,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen,361005,China
2.Department of Physics,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
3.Department of Chemistry,University College London,London,20 Gordon Street,WC1H 0AJ,United Kingdom
4.Thomas Young Centre,University College London,London,Gower Street,WC1E 6BT,United Kingdom
5.Diamond Light Source Ltd.,Harwell Science and Innovation Campus,Didcot,OX11 0DE,United Kingdom
6.Fujian Key Laboratory of Materials Genome,College of Materials,Xiamen University,Xiamen,361005,China

Zhang，Jiaye,Willis，Joe,Yang，Zhenni,et al. Direct determination of band-gap renormalization in degenerately doped ultrawide band gap ?- Ga2 O3 semiconductor[J]. Physical Review B,2022,106(20).

Zhang，Jiaye.,Willis，Joe.,Yang，Zhenni.,Sheng，Ziqian.,Wang，Lai Sen.,...&Zhang，Kelvin H.L..(2022).Direct determination of band-gap renormalization in degenerately doped ultrawide band gap ?- Ga2 O3 semiconductor.Physical Review B,106(20).

Zhang，Jiaye,et al."Direct determination of band-gap renormalization in degenerately doped ultrawide band gap ?- Ga2 O3 semiconductor".Physical Review B 106.20(2022).