Photoelectronic properties of orthorhombic undoped κ-Ga2O3 epitaxial thin films, grown on sapphire substrates by metal-organic vapour phase epitaxy, were evaluated under X-ray irradiation (CuKα line, 8.05 keV) for the first time. Photoresponse linearity at low dose-rates (varying in the 10-200 μGy s−1 range), and excellent detection sensitivity (up to 342.3 μC Gy−1 cm−3), were demonstrated even at very low applied electric fields (down to 0.001 V μm−1). Photocurrent rise time was evaluated to be <0.5 s, and signal stability was assessed for exposure times up to 2 h, highlighting no degradation of the performance. These encouraging results, mostly due to the extremely low dark current measured (in the pA range), suggest that orthorhombic undoped κ-Ga2O3 is a promising material for the fabrication of sensitive and stable large-area X-ray detectors with minimum power consumption.
Girolami, M., Bosi, M., Serpente, V., Mastellone, M., Seravalli, L., Pettinato, S., et al. (2023). Orthorhombic undoped κ-Ga2O3 epitaxial thin films for sensitive, fast, and stable direct X-ray detectors. JOURNAL OF MATERIALS CHEMISTRY. C, 11(11), 3759-3769 [10.1039/d2tc05297k].
Orthorhombic undoped κ-Ga2O3 epitaxial thin films for sensitive, fast, and stable direct X-ray detectors
Girolami, Marco
;Serpente, Valerio;Salvatori, Stefano;
2023-01-01
Abstract
Photoelectronic properties of orthorhombic undoped κ-Ga2O3 epitaxial thin films, grown on sapphire substrates by metal-organic vapour phase epitaxy, were evaluated under X-ray irradiation (CuKα line, 8.05 keV) for the first time. Photoresponse linearity at low dose-rates (varying in the 10-200 μGy s−1 range), and excellent detection sensitivity (up to 342.3 μC Gy−1 cm−3), were demonstrated even at very low applied electric fields (down to 0.001 V μm−1). Photocurrent rise time was evaluated to be <0.5 s, and signal stability was assessed for exposure times up to 2 h, highlighting no degradation of the performance. These encouraging results, mostly due to the extremely low dark current measured (in the pA range), suggest that orthorhombic undoped κ-Ga2O3 is a promising material for the fabrication of sensitive and stable large-area X-ray detectors with minimum power consumption.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.