Tailorable band-tail emissions in PLD a-SiC films

The variation of He deposition pressure (vacuum, 10-2 and 1 mbar) induces stoichiometric changes in PLD a-SiC film transforming them from stoichiometric to C-rich SiC. The SiC films exhibited broad band Photoluminescence (PL) at room temperature where PL peak exhibited blue shift from 1.8 eV to 2.2 eV with increase in atomic percentage of C from 49.4 to 62.4 %. The variation of PL peak position and intensity of SiC films with band gap as well as Urbach energy reveals that the origin of the observed PL is due to band tail emissions from amorphous SiC structures.