Influence of hydrostatic pressure on the platinum levels in silicon

Platinum diffusion gives rise to three energy levels in our silicon samples. Deep-level transient spectroscopy detects acceptor levels at $E_c-235\mathrm{}$ meV and $E_c-500\mathrm{}$ meV, and a donor level at $E_v+320\mathrm{}$ meV. The energy shift under hydrostatic pressure for either level was measured for pressures up to 0.50 GPa. The Pt acceptor at $E_c-235\mathrm{}$ meV reveals the same pressure coefficient as was already reported for the well-known $A$ center. This common property supports the recently proposed model of a vacancy-related structure for the substitutional Pt.