Surface recombination and space-charge-limited photocurrent-voltage (PC-V) measurements in (Cd,Mn)Te samples. Kinetics of photocurrent (PC)

Photocurrent-voltage characteristic (PC-V) is a method of determining the critical parameter in X-ray and gamma-ray detector plates, i.e., the carrier mobility - lifetime product, mt. We show on the (Cd,Mn)Te samples that the measurement results depend strongly on the surface treatment and the charge space distribution. The PC-V characteristics obtained for hv > Eg and hv ~ Eg indicated that etching with 20% HCl caused an appearance of a significant concentration of very shallow surface traps at the (Cd,Mn)Te sample surface. These traps seriously changed the measurements of PC-V characteristics and PC kinetics. We also noticed a small contribution of holes to photoconductivity in the PC kinetics. The PC-V characteristics measurements for hv > Eg may test the detector plate surface quality.

Andrzej Mycielski, Dominika M. Kochanowska, Aneta Wardak, Krzysztof Goscinski, Michal Szot, Witold Dobrowolski, Gabriela Janusz, Malgorzata Gorska, Lukasz Janiak, Wieslaw Czarnacki, Lukasz Swiderski, Joanna Iwanowska-Hanke, Marek Moszynski · 2022