Abstract
Infrared transmission measurements of GaP with S or Si donor impurities at liquid-helium temperature reveal absorption lines due to excitation of the donor electron. Strong absorption peaks corresponding to the transition are observed, and their spectral positions are used to determine optical ionization energies of 104.2 and 82.5 meV (±0.3 meV), respectively, for S and Si donors in GaP. A fitting of Faulkner's effective-mass calculation for donor states to the observed levels yields the effective masses of the conduction band: and . The -like final states observed in these measurements are found to differ significantly in binding energy from the excited donor-electron states observed in the "two-electron" recombination of the exciton bound to neutral sulfur in GaP.
- Received 22 April 1969
DOI:https://doi.org/10.1103/PhysRev.186.786
©1969 American Physical Society