title: Thermoreflectance characterization of beta-Ga2O3 thin-film nanostrips.
abstract: Nanostructure of beta-Ga(2)O(3) is wide-band-gap material with white-light-emission function because of its abundance in gap states. In this study, the gap states and near-band-edge transitions in beta-Ga(2)O(3) nanostrips have been characterized using temperature-dependent thermoreflectance (TR) measurements in the temperature range between 30 and 320 K. Photoluminescence (PL) measurements were carried to identify the gap-state transitions in the beta-Ga(2)O(3) nanostrips. Experimental analysis of the TR spectra revealed that the direct gap (E(0)) of beta-Ga(2)O(3) is 4.656 eV at 300 K. There are a lot of gap-state and near-band-edge (GSNBE) transitions denoted as E(D3), E(W1), E(W2), E(W3), E(D2), EDBex, E(DB), E(D1), E(0), and E(0)' can be detected in the TR and PL spectra at 30 K. Transition origins for the GSNBE features in the beta-Ga(2)O(3) nanostrips are respectively evaluated. Temperature dependences of transition energies of the GSNBE transitions in the beta-Ga(2)O(3) nanostrips are analyzed. The probable band scheme for the GSNBE transitions in the beta-Ga(2)O(3) nanostrips is constructed.
authors: Graduate Institute of Engineering, Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan. chho@mail.ntust.edu.tw
authors: Ching-Hwa
authors: CH
authors: Ho
authors: Chiao-Yeh
authors: CY
authors: Tseng
authors: Li-Chia
authors: LC
authors: Tien
mesh_terms: D003198:Computer Simulation; D008027:Light; D049449:Luminescence; D049329:Nanostructures / Q000737:chemistry*; D013696:Temperature