Table of Contents
VLSI Design
Volume 8, Issue 1-4, Pages 153-157

Numerical Examination of Photon Recycling as an Explanation of Observed Carrier Lifetime in Direct Bandgap Materials

1Microelectronics Research Center, Georgia Institute of Technology, Atlanta 30332, GA, USA
2lTT Night Vision, Roanoke 24019, VA, USA

Copyright © 1998 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Photon recycling is examined as an explanation for the observed large carrier lifetimes in an InP/InGaAs photodiode. This effect extends the effective carrier lifetime within a device by re-absorbing a fraction of the photons generated through radiative band-toband recombination events. In order to predict the behavior of this carrier generation, photon recycling has been added to our two-dimensional macroscopic device simulator, STEBS-2D. A ray-tracing preprocessing step is used to map all of the possible trajectories and absorption of various wavelengths of emitted light from each originating node within the device. The macroscopic simulator uses these data to determine the spatial location of the re-absorbed 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 obtained. A practical application of this model is presented where the effects of photon recycling are used as a possible explanation of the discrepancy between the theoretically predicted and experimentally observed radiative recombination rate in a double heterostructure photodetector.