Specific features of recombination on centers inside disordered regions

The paper considers the recombination processes involving disordered regions (DR's). A general expression for the lifetime tausub(r) with respect to recombination on DR's at low injection levels is obtained under the assumption of one recombination level existing inside the DR. Analysis is made of the dependence of the lifetime tausub(r) on the equilibrium height of the potential barrier and the location of the Fermi level μ. The rate of recombination on DR's is found to be maximum at psi0 psi0sup(min) where psi0sup(min) is determined by the recombination center parameters and the majority carrier concentration is undamaged material. The temperature and injection dependences of the lifetime are considered. The DR's are shown to introduce additional asymmetry into the trapping cross-sections. Trapping on the centers inside a DR is considered. The DR's are proposed to be classified as 'recombination DR's' when psi0 approximately equal to psi0sup(min), and 'trapping DR's' when psi0 > psi0sup(min). The effective lifetime tausub(eff) is calculated. It is shown that tausub(eff) = tausub(M) (1 - tauμ/tausub(r)). The limits of applicability of the expressions derived are discussed. (author)