A theoretical study of resonant tunneling in multilayered Ga1−xAlxAs/GaAs structures is presented. The spectrum of resonant energies and its dependence on the barrier structure are analyzed from calculated profiles of barrier transparency versus energy, and from current–voltage characteristics computed at selected temperatures and Fermi levels. The present formalism is based on the effective mass approximation as done to date, but contains three significant improvements: a more realistic treatment of the spatial dependence of effective masses and band edges; the recognition of the special dynamical role played by the transverse energy as a consequence of the difference in itinerant two dimensional carrier motion from layer to layer; and the avoidance of plane-wave or WKB approximations for calculating the wave function in favor of direct numerical evaluation. It is shown that these revisions lead to quantitative differences with results of previous work.

No abstract

Recombination radiation in GaAs diodes has been found proportional to the forward diode current at current levels where the recombination radiation is dominant, implying an efficient conversion from injected electrons to band-edge photons. A visible red radiation has been observed from these diodes at high forward diode currents.

Long-term operating-life data are reported for (AlGa)As cw laser diodes. The use of half-wave Al2O3 facet coatings is shown to eliminate facet erosion, allowing stable diode operation at constant current for periods in excess of 10 000 h.

No abstract