Multiple Bound Exciton Associated with the Nitrogen Donor in 3C Silicon Carbide

PL emissions related to multiple bound exciton complexes (MBEC) have been observed in 3C SiC, using time-resolved photoluminescence spectroscopy. At low temperatures we observe transition from MBECm complexes with up to five (m = 5) electron–hole pairs. The observed emission is due to the recombination of one electron–hole pair in the complex. The time decay of these emissions decreases with increasing m, ranging from 160 ns to 21 ns. For phonon-assisted emissions we observe additional splitting of the MBEC due to excited electron states. The observed PL emissions and their time decay can be explained according to the shell model. All emissions within each shell have similar decay times, due to fast relaxation of the electrons inside each shell. Multiple bound excitons have not been clearly observed in the 4H or 6H polytype of SiC.