Energy Level Structure of Amorphous Silicon Carbide

The photoluminescence spectra of amorphous SiC films have been studied. The films were fabricated by the plasma-enhanced chemical vapor deposition method. The energy scheme of amorphous SiC has been proposed. This scheme contains a donor state at 0.1 eV and two acceptor states at 0.27 eV and 0.34 eV. It is shown that acceptor electronic states are due to Si–H and C–H bonds. Experimental data confirming this energy scheme are given. Blue photoluminescence (λmax=5100 A) is observed in amorphous SiC films prepared at a high-frequency discharge power of more than 200 W. It is shown, that this is caused by the increase of carbon concentration.