Minority carrier diffusion length, lifetime and mobility in p-type GaAs and GaInAs

Minority carrier diffusion lengths and lifetimes were determined for p-type Ga(1-x)InxAs with an In-content of 0 <= x <= 0.53 by cathodoluminescence and time-resolved photoluminescence measurements respectively under low injection conditions; the resulting minority carrier mobilities are also reported. Highly p-doped samples (3 x 10(18) cm(-3)) demonstrate a constant minority carrier diffusion length of (5.0 +/- 0.7) mu m and a constant lifetime of (3.7 +/- 0.7) ns for an In-content up to 21%. Lower doped samples (3 x 10(17) cm(-3)), on the other hand, show an increase in minority carrier diffusion length and lifetime with In-content from (6.3 +/- 0.2) mu m and (6.2 +/- 0.5) ns respectively for GaAs to (14 +/- 2) mu m and (24.4 +/- 0.5) ns respectively for Ga0.79In0.21As. Increasing the In-content to 53% results in a drop in the minority carrier diffusion length independently of the p-doping concentration. This is interpreted as a change in the energy of the Shockley-Read-Hall trap levels within the bandgap as a function of indium concentration. Published by AIP Publishing.