Silicon Bandgap Energy Research Articles

Photoionization cross sections in platinum-doped silicon

Platinum-doped silicon has been investigated using photocurrent and photocapacitance measurements. In all samples, at least two deep energy levels having the same concentration were found, 0.250 eV below the conduction band and 0.355 eV above the valence band, respectively. The other thresholds were 0.908 and 0.82 eV, respectively. The threshold energies of the energy levels add up to values of 1.158 and 1.175 eV, respectively, which are close to the band-gap energy of silicon (1.166 eV) at 80 K. No further deep level impurities could be detected in these samples. In some other samples, up to six different deep energy levels were found with more than two order of magnitude difference in concentration. Although five of these energy levels have been reported in the literature, no proof could be given that they are due to platinum.