Spectroscopic Study of Tellurium Donors in GaP

The 1s(A₁)→2p₀ and 2p_± transitions in Te donors in GaP have been observed. Together with similar data for Si and S donors, Faulkner's effective-mass (EM) calculations yield an ionization energy of 89.8±{}0.3 meV for Te donors. Conduction-band effective masses consistent with all the data for these GaP donors are m_⊥=(0.180±0.005)m₀ and mII=(1.5±0.2)m₀. The effects of uniaxial stress on the "two-electron" transitions in the recombination of excitons bound to neutral Te donors in GaP are consistent with the final donor states observed being s-like with a valley-orbit splitting.