Electrical characterization of CdTe pixel detectors with Al Schottky anode

Abstract

a b s t r a c tPixelated Schottky Al/p-CdTe/Pt detectors are very attractive devices for high-resolution X-ray spectroscopic imaging, even though they suffer from bias-induced time instability (polarization). In this work, we present the results of the electrical characterization of a (4 Â 4) pixelated Schottky Al/p-CdTe/Pt detector. Current-voltage (I-V) characteristics and current transients were investigated at different temperatures. The results show deep levels that play a dominant role in the charge transport mechanism. The conduction mechanism is dominated by the space charge limited current (SCLC) both under forward bias and at high reverse bias. Schottky barrier height of the Al/CdTe contact was estimated by using the thermionic-field emission model at low reverse bias voltages. Activation energy of the deep levels was measured through the analysis of the reverse current transients at different temperatures. Finally, we employed an analytical method to determine the density and the energy distribution of the traps from SCLC current-voltage characteristics.

Numerical analysis of degradation kinetics in CdTe thin films

“…They could reverse the electric field polarity at the junction (by etching, applying a bias and heating) to sweep away the accumulated excess carriers and recover V oc . A similar approach was proposed by Turturici et al to model the bias-dependent degradation of CdTe photodetectors under polarization (Turturici et al, 2014). By assuming that the defect density (deep trap acceptors) changes as N À ðtÞ ¼ N 0 1 À exp À t s À Á À Á , they derived a time-dependent electric field model as EðtÞ ¼ qN À ðtÞd=2 0 where d is the CdTe thickness.…”

A digital approach for real time high-rate high-resolution radiation measurements

“…We performed X-ray spectra measurements, at both low and high ICRs, with a thin planar CdTe detector [20]. As well known, thin CdTe/CdZnTe detectors (1-2 mm thick) are very appealing for X-ray spectroscopy in the 1-100 keV energy range [40][41][42][43][44][45][46][47]. We used a planar CdTe detector (XR100T-CdTe, S/N 6012, Amptek, USA) with a thickness of 1 mm (absolute efficiency of 64% at 100 keV) and equipped with a resistive-feedback CSP.…”

“…G. Gerardi, L. Abbene / Nuclear Instruments and Methods in Physics Research A 768 (2014)[46][47][48][49][50][51][52][53][54] …”

Characterization of the metal–semiconductor interface of gold contacts on CdZnTe formed by electroless deposition

“…A quasi-Ohmic voltage dependency is one where I is linearly proportional, but not equal to V/R. The final region, at the largest bias, had a quadratic voltage dependency indicative of space-charge limited (SCL) injection at the contacts [44][45][46][47][48].…”