A study was made of the effect of hydrostatic pressures, upon defect states in such semiconductors, by using the 3-band Kane model. It was shown that shifts, under pressure, of the energy levels of centers with various symmetries were different. The h-center level strictly followed the v-band top. On the other hand, the l-c level shift depended upon the pressure in a more complicated way, and was governed by system parameters. The transition from resonance to localized defect states, due to the transition from gap-less to narrow-gap semiconductors under hydrostatic pressures, was also studied.

M.V.Strikha, F.T.Vasko: Physica Status Solidi B, 1994, 181[1], 181-8