  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.
