Impurity Effect on Recombination Processes in InP

The effects of impurities (S, Sn, Fe and Zn) doped in InP on recombination processes were investigated using photoluminescence (PL) and photoacoustic (PA) spectroscopies. The recombination processes were affected by the impurity levels in the bandgap and by the large strain which was induced by the impurities in InP. The processes were radiative for InP with shallow impurity levels such as S-doped and Sn-doped samples and nonradiative for InP with deep impurity levels such as Fe-doped and Zn-doped samples. The results of PL and PA measurements were in a reciprocal correlation. However, both spectra were observed for undoped InP with large strain induced by impurities such as Si. These relationships were explained using three types of configuration coordinate diagram.