Heavy and light hole minority carrier transport properties in low-doped n-InGaAs lattice matched to InP

TL;DR

This paper reports on the measurement of minority carrier diffusion lengths, mobilities, and lifetimes for heavy and light holes in low-doped n-InGaAs, revealing their different transport behaviors and dominance at various diffusion distances.

Contribution

The study introduces a simple electrical technique to separately extract heavy and light hole transport properties in low-doped n-InGaAs.

Findings

Heavy holes have a diffusion length of 54.5 microns.

Light holes have a diffusion length exceeding 140 microns.

Heavy holes exhibit a mobility of 692 cm2/Vs.

Abstract

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.