Energy dependence of the carrier capture coefficient for neutral shallow impurities in semiconductors

Abstract

The authors' consider the effect of carrier resonance scattering in slightly doped compensated semiconductors on the carrier capture by neutral shallow impurities, resulting in the formation of H--like centres. The energy dependence of the capture coefficient alpha ( epsilon ) exhibits a weak maximum at Ei, the carrier affinity to the H--like centre. The photoconductivity and photo Hall effect are studied for Si:B samples with a boron concentration NA<1016 cm-3 and a degree of compensation K<10-3 at liquid helium temperature in 'heating' electric fields. The obtained energy dependence of the hole capture coefficient for neutral boron atoms is in agreement with the authors' calculations.