Optical-electrical characteristics of Al/Gd2O3/(CZ-pSi)/Al diodes under gamma ray irradiation

This article aimed to report the results on the properties of Gd2O3/(CZ-pSi) diodes under various gamma ray irradiation dose rates (3, 6, 12, 18, 24, 30, 36, 42, 50 Gy). n-type Gd2O3 films were deposited on a p-type Czochralski-grown monocrystalline silicon (CZ-pSi) wafers by pulsed laser deposition (PLD) technique with varying building laser energies (500, 600, 700, 800, 900 mJ) at room temperature and pressure (3.3 x 10(-2) Pa). Amorphous structures were perceived for all films by XRD. Band gaps of the films were modified by controlling the amount of Gd2O3 on CZ-pSi wafers by laser power during deposition and determined to be between 5.30 and 5.75 eV. The Gd2O3/(CZ-pSi) films were irradiated by a Co-60 gamma-ray source system. The current and voltage (I-V) measurements, before and after irradiation (0-50 Gy), indicated that the current decreases toward zero with increasing doses. Capacitance and voltage (C-V) measurements at frequencies of 10-1000 kHz before and after irradiation showed a shift towards the right side of the pre-irradiation curves for each film. The shift was observed in both I-V and C-V curves with increasing radiation doses at 100 kHz as the average of the frequencies used. Contrary to the decrease in current curves, there was an upward increase in capacitance curves of all films with increasing radiation dose. The best build-in potentials of 0.1 V (800 mJ), 1.2 V (500 mJ) and 1.4 V (600 mJ) were obtained for the laser deposition powers of the Gd2O3/(CZ-pSi) diodes. These results are promising for diodes to be used in the radiation detection applications such as in neutron and alpha particles detectors.

Automated summary

This article reports the properties of Gd2O3/(CZ-pSi) diodes under various gamma ray irradiation dose rates. The band gaps of the films were modified by controlling the amount of Gd2O3 during deposition. The current decreases while the capacitance increases with increasing radiation dose. These results are promising for radiation detection applications.