High leakage currents and incomplete charge collection limit the performance of detectors obtained from bulk semiinsulating (SI) GaAs. In this contest, a crucial role is played by the electron limiting contact. We have investigated the effect of an epitaxial p-type layer deposited on the semi-insulating substrate in place of the usual Schottky contact. Electrical characterization evidences an effect of the p-layer only at low voltages, but radiation detection experiments show an improvement of the charge collection efficiency, which is function of the doping level of the p-layer. In particular both alpha and chi irradiations give evidence of gain mechanisms in the collected charge. From these results, the strong relation between the structure of the electron-blocking interface and the charge collection properties of these detectors comes out.
|Autori:||Cola A; Quaranta F; Fucci R; Melone G; Rossi R; Passaseo A; Conti M; Mettivier G; Russo P; Bisogni M; Fantacci M|
|Titolo:||SI-GaAs detectors with epitaxial junction RID G-2379-2010|
|Anno del prodotto:||1999|
|Digital Object Identifier (DOI):||10.1109/23.775509|
|Appare nelle tipologie:||1.1 Articolo in rivista|