Charge carrier mobility fluctuations due to the capture–emission process

Abstract

It is shown that the free charge carrier capture–emission process causes both the charge carrier density and mobility fluctuations. In this report we present the calculation results in order to find how the capture–emission process affects the free charge carrier mobility and mobility fluctuations. The carrier mobility dependence on phonon, impurity and carrier–carrier scatterings, and the mobility dependence on the electric field and the energy gap variation due to the doping level were taken into account. It is also shown that fluctuations of the charge carrier density and mobility due to the capture–emission process are completely correlated, and that their relaxation times are the same as for the charge capture–emission process. The general expression for estimation of active capture centre density in the volume of a homogeneous sample from the low-frequency noise measurements is presented.

Low-Frequency Noise Investigation of 1.09 μm GaAsBi Laser Diodes

“…Low-frequency electrical fluctuations of the group B LDs are distinguished by 1/ f α -type spectra in the entire investigated current region, where index α ranges from 0.9 to 1.4 ( Figure 5 a). In semiconductor devices, the 1/ f α -type fluctuations originate from the superposition of Lorentzian-type spectra due to different charge carrier generation-recombination or capture-emission processes having wide distribution of relaxation times [ 19 , 20 , 21 ]. The electrical noise spectra of group A LDs, as it can be seen from Figure 5 b, are also 1/ f α -type in a forward current range up to the second bump.…”

Generation-recombination noise and other features of doped silicon in a wide temperature range

“…In Ref. [18], it is demonstrated that the charge carrier capture-emission process is the main source of the low-frequency noise in homogeneous semiconductors and this process can produce the free charge carrier mobility fluctuations in particular cases [19].…”