Comparison of HgI2, CdTe and Si (p-i-n) X-ray detectors

This paper presents a comparison of HgI2, CdTe and Si (p-i-n) detector technologies for use in X-ray spectroscopy applications in terms of the basic material properties, the detector fabrication techniques and the spectral responses achieved. The requirements imposed on the detector technologies by the design and construction of portable, hand-held instrumentation are discussed. A number of new spectral results are shown. For example, the energy resolution of 596 eV FWHM at 59.5 keV obtained with CdTe (p-i-n) detectors and the energy resolution of 415 eV FWHM at 22 keV measured with HgI2 structures are reported. A discussion of the various practical applications with the above detector technologies is presented.