2-DIMENSIONAL MODEL OF PHOTON RECYCLING IN DIRECT-GAP SEMICONDUCTOR-DEVICES

The effects of photon recycling are examined in a general, fully numer ical, two-dimensional model accounting for the detailed geometry of th e device and the spectral content of the recombined excess carriers. T he primary component of this model is a three-dimensional ray tracing algorithm which encompasses effects such as wavelength dependent absor ption and index of refraction, the angular dependence of transmissivit y between layers in a heterostructure device, and multiple reflections within a device. This ray tracing preprocessing step is used to map a ll of the possible trajectories and absorption of various wavelengths of emitted light from each originating node within the device. These d ata are integrated into a macroscopic device simulator to determine th e spatial and temporal location of the reabsorbed radiation within the geometry of the device. By incorporating the ray tracer results with the total quantity and spectral content of recombined carriers at each node within the simulation, the recycled generation rate can be obtai ned. To demonstrate the use of this model, the effects of photon recyc ling on the carrier lifetime in an InP/InGaAs double heterostructure p hotodiode are presented. Good agreement between the experimentally mea sured lifetime and that predicted using photon recycling is obtained. (C) 1997 American Institute of Physics.