Multielement X-ray row detector on GaAs with spatial resolution of 108μm

Use of epitaxial gallium arsenide in detectors

“…Such investigations have been performed at the Institute of Radio Engineering and Electronics of the Russian Academy of Sciences [5]. Here, x-ray detectors on the basis of epitaxial GaAs structures and operating in the photovoltaic regime [6] at room temperature with no bias voltage, which is important for ensuring low noise levels, were developed.…”

“…A spatial resolution of 1.2 mm −1 is sufficient for fluorography [6]. For a mammography, this quantity must be less than 5 mm −1 [7].…”

“…For resolution 1.2 mm −1 , an x-ray multielement lineal detector with a 400 µm step has been fabricated on the basis of epitaxial GaAs with a 100 µm thick active absorption layer. Such a detector based on epitaxial GaAs structures (p + -n-n i -n + ), which consists of a series of pixels combined with reading electronics, and is intended for discrete recording of an x-ray image [6,7].…”

“…It is shown in [5][6][7] that the photon detection efficiency can be increased if the channel of the detector is 5-10 mm long and the detector makes an angle with the x-ray radiation. Then, for the same aperture, the photoresponse will be proportional to 1/cosθ, where θ is the angle of incidence of the x-ray photons.…”