A Novel Extraction Procedure of Contact Characteristic Parameters from Current–Voltage Curves in CdZnTe and CdTe Detectors

Abstract

The estimation of the characteristic parameters of the electrical contacts in CdZnTe and CdTe detectors is related to the identification of the main transport mechanisms dominating the currents. These investigations are typically approached by modelling the current–voltage (I–V) curves with the interfacial layer–thermionic-diffusion (ITD) theory, which incorporates the thermionic emission, diffusion and interfacial layer theories into a single theory. The implementation of the ITD model in measured I–V curves is a critical procedure, requiring dedicated simplifications, several best fitting parameters and the identification of the voltage range where each transport mechanism dominates. In this work, we will present a novel method allowing through a simple procedure the estimation of some characteristic parameters of the metal–semiconductor interface in CdZnTe and CdTe detectors. The barrier height and the effects of the interfacial layer will be evaluated through the application of a new function related to the differentiation of the experimental I–V curves.

High performance platinum contacts on high-flux CdZnTe detectors

“…To measure the main characteristic parameters of the electrical contacts (barrier height, barrier lowering, interfacial layer properties), we analysed the measured I–V curves through the application of a new procedure reported in Ref. 17 . This method allows to extract contact characteristic parameters in metal/semiconductor structure, such as CZT detectors, where the electrical currents follow the interfacial layer–thermionic-diffusion (ITD) model theory 22 , 23 .…”

“…Selecting the appropriate electrode material is essential for minimizing the leakage currents. Despite several studies have been carried out reporting electrical characterization of contacts on standard LF-CZT detectors 11 – 16 , only few studies were performed on HF-CZT 17 .…”

Development of travelling heater method for growth of detector grade CdZnTe single crystals

“…Cadmium zinc telluride (CdZnTe) is one of the most promising room-temperature semiconductor gamma radiation detector material due to its wide energy band gap and high atomic number [1][2][3][4]. The research activities carried out on detector technology over the past few decades have showcased that CdZnTe is an excellent substitute for scintillation detectors in terms of high sensitivity, better energy resolution and high spatial resolution at room temperature [4][5][6][7]. In the recent past, CdZnTe detector with an energy resolution of less than ≈ 0.5 % at 662 keV of 137 Cs had already been demonstrated [7] and commercial detectors are also available in the market.…”