LASER TRANSITION AND WAVELENGTH LIMITS OF GAAS

Data are presented showing the variation at 77°K in GaAs laser photon energy, and the laser recombination process, as a function of doping concentration from the lowest dopings now possible to the highest donor, acceptor, and donor-acceptor (compensated) dopings which still yield crystals of laser quality. GaAs is shown to be capable of laser operation over a range exceeding 1200 Å (λmin≤7880 Å to 9100 Å ≤ λmax). Experimental data on n-type crystals are used to approximate the position of the Fermi level. Data on p-type and compensated crystals are used to approximate the depth of donor tail states involved in laser action. These results agree reasonably well with the values calculated from the metallic hydrogen model. Laser photon-energy data on uniformly doped p-type crystals are presented which indicate the extent to which acceptor states involved in laser operation penetrate into the forbidden gap. © 1969 The American Institute of Physics.