THE INFLUENCE OF DISLOCATIONS ON MERCURY SELF-DIFFUSION IN EPITAXIAL AND BULK GROWN CDXHG1-XTE

Mercury self-diffusion in CdxHg1-xTe was studied using radiotracers between 250 and 400-degrees-C. Diffusion profiles were found to have two components and contact autoradiography was used to relate the tail component of bulk samples to short circuit diffusion via dislocation arrays. Dislocation analysis was used to characterise diffusion tails and estimate the mercury diffusion coefficient within the defect structure, D'(Hg). Temperature variation of the lattice diffusion coefficient, D(Hg), was measured under saturated mercury partial pressure and found to obey the equation D(Hg) = 2 x 10(-4) exp{-1.1 eV/kT} cm2 s-1. Surface concentration of diffused mercury in epitaxial samples was routinely about a factor of 40 lower than bulk grown CdxHg1-xTe.