Photon recycling and recombination processes in 0.53 eV p-type InGaAsSb

Transient radio frequency photoreflectance measurements were performed on 0 .53 eV p-type InGaAsSb double heterostructures, grown by organometallic vap or phase epitaxy on lattice matched GaSb substrates, for determining excess carrier lifetime. Direct evidence of photon recycling was observed by chan ging the GaSb backsurface reflectivity and observing the change in excess c arrier lifetime. Consistent with theory developed for this type of structur e, effective lifetimes increased by 30%-40% when the backsurface was change d from an absorbing to a reflecting surface. The theory develops a closed-f orm expression for the total radiative recombination rate, starting with co ntinuity equations for both excess minority carriers and the photon density . Lifetime measurements in these p-InGaAsSb structures with different dopin g concentrations and epitaxial layer thicknesses allow the extraction of mi nority carrier recombination parameters. Measurements indicate a value for the radiative recombination coefficient of B=5-6x10(-11) cm(3)/s, for the A uger recombination coefficient of C=2-5x10(-29) cm(6)/s, for the Shockley-R ead-Hall lifetime of 100-150 ns and for the surface recombination velocity of 1-2x10(3) cm/s. (C) 2001 American Institute of Physics.