High spatial resolution graded-gap AlxGa1-xAs X-ray detector

摘要

Spatial resolution of two types of graded-gap AlxGa1-xAs X-ray detectors, p(+)-AlxGa1-xAs layer (A type) and lp-AlxGa1-xAs-p(+)-GaAs-p-AlxGa1-xAs structure (B-type), is investigated. Two processes, the diffusion of generated charge and broadening of light beam, cause blurring of X-ray image in the detectors. Optical broadening of light beam was eliminated in B-type structure. The value of spatial resolution mainly depends on the thickness of graded-gap AlxGa1-xAs layer. Spatial resolution of 10 LP/mm for the A-type structure of 50 mu m thickness and 25 LP/mm for B-type structure of 18 mu m thickness was experimentally observed. (c) 2006 Elsevier B.V. All rights reserved.