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Highly resistive undoped p-type gallium oxide samples were subjected to cumulative proton irradiation with energies ranging from 25 to 70 keV and doses in the 1.6 × 1014–3.6 × 1014 cm−2 range. Proton irradiation resulted in up to a factor of 2 reduction of minority electron diffusion length in the samples for temperatures between ∼ 300 and 400 K. Electron injection into the samples under test using a scanning electron microscope beam leads to pronounced elongation of diffusion length beyond the pre-irradiation values, thus demonstrating stable (days after injection) recovery of adverse radiation impact on minority carrier transport. The activation energy of 91 meV estimated from the temperature dependent diffusion length vs electron injection duration experiments is likely related to the local potential barrier height for native defects associated with the phenomenon of interest.

Cd1-xMnxTe is a promising material that has been introduced as a potential successor for the popular Cd1-xZnxTe material in the field of room-temperature gamma-ray detection. In this work, we demonstrate a planar array on a 5 mm thick Cd1-xMnxTe detector with spectroscopy performance similar to that of industrial Cd1-xZnxTe devices of the same thickness. The uniformity of Cd1-xMnxTe was theoretically predicted and experimentally demonstrated to be superior to that of Cd1-xZnxTe due to a better solubility of manganese. The main challenge until now was to exhibit large area, thick Cd1-xMnxTe arrays with satisfactory spectroscopy performance. In this Letter, static as well as spectroscopic properties of thick Cd1-xMnxTe devices are compared to those of conventional Cd1-xZnxTe detectors, grown by the same technology (horizontal Bridgman).

In this work, experimental characterization results of indium nano-contacts are presented. The indium nano-contacts are epitaxially grown on a two-dimensional surface of high-resistivity, n-type Cd0.9Zn0.1Te in ultra-high vacuum. The scaling effect in these contacts is systematic, but not linear. It is shown that the contacts exhibit a profoundly asymmetric behavior. It is argued that the “rectifying” behavior of these contacts is due to tunneling and that the tunneling does not necessarily imply Schottky nature.

We used in situ scanning tunneling microscopy to monitor in real time the formation of nano-rings at the molecular beam epitaxially grown In/CdZnTe(110) surface, and Auger electron spectroscopy to explore the corresponding compositional changes. In-diffusion of In and segregation of Cd to the surface in course of annealing lead to a formation of elliptically distorted nano-rings, elongated along the fast [1¯10] diffusion direction. Exacerbated diffusion anisotropy in the liquid state, at temperatures above the melting point of In, further distorts the nano-rings into a camel-hump shape.

The subject of surface leakage and passivation in spectrometers fabricated in high pressure Bridgman CdZnTe crystals with evaporated gold contacts has been examined. The surface leakage has been found to be the dominant mechanism of dark current leakage in metal–semiconductor–metal detectors with noninjecting contacts. Several passivation techniques have been examined with various degrees of success in terms of reducing the mean value and the power spectral density of dark noise characteristics. An insulating polymer was applied on the bare surface reducing the total leakage current by the factor of 6–7, while favorably affecting the dark noise spectral density by decreasing the corner frequency of the low frequency noise. However, a considerable surface leakage has been observed even in these apparently passivated spectrometers. A three terminal device with iso-potential high voltage contacts has been fabricated and tested, exhibiting a reduction of the total dark current leakage by approximately two orders of magnitude. With this three terminal design, the bulk resistivity of typical high pressure Bridgman crystals is correctly determined and found to be ∼2⋅1011 Ω⋅cm.