The formation of a B-related defect which was responsible for the 4B0 emission line in the low-temperature photoluminescence spectrum of 4H-type material was investigated. The 4B0 luminescence was absent from as-grown epitaxial layers. The line appeared after hydrogenation, together with other H-related lines, and disappeared after high-temperature annealing. This indicated the involvement of H in the formation of the corresponding radiative recombination center. Prolonged excitation of the hydrogenated epitaxial layers, with above-bandgap light, caused a previously reported enhanced passivation of Al acceptors plus an additional strong non-metastable increase in the 4B0 luminescence; due to recombination-enhanced formation of the corresponding defect complex.

Optically Induced Formation of the Hydrogen Complex Responsible for the 4B0 Luminescence in 4H-SiC. Y.Koshka: Applied Physics Letters, 2003, 82[19], 3260-2