Probing carrier lifetimes at dislocations in epitaxial CdTe

Dark line defects arising from dislocations in epitaxial CdTe films are known to strongly limit the overall performance of optoelectronic devices. However, their effect on carrier diffusion length and lifetime in the material immediately surrounding dislocations is not well quantified. We apply a photoluminescence imaging technique to directly measure these parameters in a CdTe/MgCdTe double heterostructure. Radiative recombination is reduced by up to 85% within 5 μm of the dislocation. Additionally, the carrier diffusion length and lifetime decrease by ∼50 and ∼80%, respectively.