  Minority carrier diffusion lengths in low-doped n-InGaAs using InP/InGaAs
double-heterostructures are reported using a simple electrical technique. The
contributions from heavy and light holes are also extracted using this
methodology, including minority carrier mobilities and lifetimes. Heavy holes
are shown to initially dominate the transport due to their higher valence band
density of states, but at large diffusion distances, the light holes begin to
dominate due to their larger diffusion length. It is found that heavy holes
have a diffusion length of 54.5 +/- 0.6 microns for an n-InGaAs doping of 8.4 x
10^15 cm-3 at room temperature, whereas light holes have a diffusion length in
excess of 140 microns. Heavy holes demonstrate a mobility of 692 +/- 63 cm2/Vs
and a lifetime of 1.7 +/- 0.2 microsec, whereas light holes demonstrate a
mobility of 6200 +/- 960 cm-2/Vs and a slightly longer lifetime of 2.6 +/- 1.0
microsec. The presented method, which is limited to low injection conditions,
is capable of accurately resolving minority carrier transport properties.
