A graded-gap photoelectric detector for ionizing radiation

Research paper by L. Dapkus, K. Požela, J. Požela, A. Šilėnas, V. Jucienė, V. Jasutis

Indexed on: 01 Feb '05Published on: 01 Feb '05Published in: Semiconductors


A heterostructure consisting of a graded-gap p-AlxGa1−xAs layer on an n-GaAs substrate is studied in relation to its role as a photoelectric-response detector of X-ray photons and α particles. It is found that the current-power sensitivity of the detector is as high as 0.13 A/W and the voltage-power sensitivity exceeds 106 V/W. The effect of preliminary irradiation with 5.48-MeV α particles (241Am) on the detector’s sensitivity is studied. It is established that the detector’s sensitivity is reduced by a factor of 1.5–2 after irradiation with α particles at a dose of 5 × 109 cm−2. A further increase in the radiation dose to 4 × 1010 cm−2 does not affect the detector’s sensitivity.