J. Phys. Cond. Matt. 3, 5143-5152 (1991)

SCI

The role of impurity correlation in auger recombination in heavily doped semiconductors

D. N. Quang

A theory has been developed for describing the influence of correlation in the impurity distribution on Auger processes in heavily doped semiconductors. The case when correlation exists because of Coulomb interactions between charged donors and acceptors as well as free carriers during the thermal preparation of the sample is considered. Taking into account both high-temperature ionic correlation and low-temperature electronic screening, the analytic dependence of the mean square of the impurity potential fluctuations on experimental conditions such as the doping concentration, compensation and excitation levels, temperature and growth condition of the sample is obtained. It is shown that for strongly compensated semiconductors the Auger coefficient may be, owing to the impurity correlation, diminished considerably by up to several orders of magnitude at heavy doping (5 x 10(18) cm-3 or above) and low excitation (below 10(16) cm-3). Moreover, the correlation effect in wide-band-gap materials is found to be far larger than that in narrow-band-gap materials.