Minority carrier diffusion length in undoped p-type epitaxially grown CdxHg1-xTe

High minority carrier lifetimes in diffusion limited p-n photodiodes result in low dark currents and a high R0A figure of merit. Minority carrier diffusion length should be an important indicator of device performance through its link with the minority carrier lifetime. The diffusion length can be measured directly on a p-n junction device using electron beam induced current (EBIC) measurements. This paper compares diffusion lengths in epitaxially grown CdxHg1-xTe measured directly using EBIC, with those predicted from both transient and steady state lifetime measurements using Einstein's relation. In all cases, as-grown layers are vacancy-doped p-type.