Electrical Characterization of CdTe pixel detectors with Al Schottky anode

Pixelated Schottky Al/p-CdTe/Pt detectors are very attractive devices for high-resolution Xrayspectroscopic imaging, even though they suffer from bias-induced time instability (polarization). Inthis work, we present the results of the electrical characterization of a (4x4) pixelated Schottky Al/p-CdTe/Pt detector. Current-voltage (I-V) characteristics and current transients were investigated atdifferent temperatures. The results show as deep levels play a dominant role in the charge transportmechanism. The conduction mechanism is dominated by the space charge limited current (SCLC) bothunder forward bias and at high reverse bias. Schottky barrier height of the Al/CdTe contact wasestimated by using the thermionic-field emission model at low reverse bias voltages. Activation energyof the deep levels was measured through the analysis of the reverse current transients at differenttemperatures. Finally, we employed an analytical method to determine the density and the energydistribution of the traps from SCLC current-voltage characteristics.