Thermally Stimulated Luminescence and Conductivity of β-Ga2O3 Crystals

Authors A. Luchechko , V. Vasyltsiv , L. Kostyk , O. Tsvetkova , B. Pavlyk

Department of Sensor and Semiconductor Electronics, Ivan Franko National University of Lviv, 107, Tarnanavskogo St., 79017 Lviv, Ukraine

Issue Volume 11, Year 2019, Number 3
Dates Received 17 January 2019; revised manuscript received 14 June 2019; published online 25 June 2019
Citation A. Luchechko, V. Vasyltsiv, L. Kostyk, et al., J. Nano- Electron. Phys. 11 No 3, 03035 (2019)
PACS Number(s) 32.30.Jc, 78.55. – m, 78.60.Kn
Keywords β-Ga2O3 single crystals, Thermostimulated luminescence, Thermostimulated conductivity, Activation energy (7) , Traps (2) .

The paper deals with thermostimulated luminescence (TSL) and thermostimulated conductivity (TSC) of unintentionally doped (UID) β-Ga2O3 single crystals. The samples under study were β-Ga2O3 single crystals grown by the floating zone method with radiation heating and then subjected to annealing in an atmosphere of oxygen or argon. The obtained photoluminescence emission spectra are typical for β-Ga2O3 single crystals: they contain the broad emission band of the host at 320-550 nm as well as a weak luminescence with maximum at 700 nm due to the unintentional Cr3+ impurities. After exposure to X-ray radiation, the samples exhibit intense TSL at the temperature range of 85-500 K. Three low-temperature peaks at 116, 147 and 165 K are present in TSL and TSC curves of these crystals. The depths of the traps responsible for these peaks are 0.15, 0.2 and 0.3 eV, respectively. The high-temperature TSL peaks at 354 K, 385 K and 430 K with corresponding activation energies of 0.84, 1.0 and 1.1 eV were observed in samples annealed in argon or oxygen atmospheres. The TSС curves are in good agreement with the results of the TSL study. A correlation between annealing of crystals in oxidizing and inert atmospheres and intrinsic defects in single crystals β-Ga2O3 has been established.

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