“…During experiments there is a controversial attitude towards the fluctuations: on one hand, own fluctuations of both voltage and current of the measuring electronic equipment, determine the threshold of sensitivity, especially during measurement of small values of the investigated parameters (it is worth mentioning that the ways to reduce fluctuations are being developed). On the other hand, fluctuations represent independent interest, since they are the basis of numerous physical [1][2][3][4][5][6][7][8][9][10] . Most of them are based on the analysis of processes at the microscopic level: fluctuations of concentration of charge carriers [3,10] ; fluctuations of mobility of charge carriers [2,7] ; capture of charge carriers by the surface energy traps [5] etc.…”