The charge carrier capture–emission process – the main source of the low-frequency noise in homogeneous semiconductors

Abstract

The possibility of determination of the number of localized capture centers of defects (relaxators) that cause low-frequency noise in a particular frequency range has been investigated. Here it is shown that a minimum number of relaxators is needed to generate 1/f type low-frequency noise only when relaxation times are arbitrarily distributed one-by-one in every two-octave range. The expression for estimation of the low-frequency noise level of the sample under test is presented. The presented expression for 1/f noise explains not only the noise level dependence both on the frequency and number of defects in the sample but also the observed noise intensity dependence on the mobility of free charge carriers. It is shown that the main source that causes low-frequency noise in homogeneous semiconductors is the charge carrier capture–emission process.