Role of new ohmic electrode metallization in detection performance of bulk semi-insulating GaAs radiation detectors

In this work, we concentrate on the study of the role of ohmic electrode metallization of radiation imaging detectors based on bulk semi-insulating (SI) GaAs. We fabricated SI GaAs radiation detectors with Ti/Pt/Au Schottky contact on one side and In/Au, Mg/Au and Gd/Au contacts on the other side of bulk material with the aim to form hole barrier Schottky contact with non-injecting effect. Current–voltage and noise characteristics and also detection performance of detectors are measured and evaluated. Observed results are discussed and compared with detector using standard AuGeNi non-alloyed ohmic metallization.