The dislocations and domains in thin ZnSe films which had been molecular beam epitaxially deposited onto GaAs(100) substrates were studied by using low-temperature cathodoluminescence imaging and spectroscopic techniques. Dark-line and bright-line defects in the low-temperature cathodoluminescence imaging of free-exciton and Y-band emissions, respectively, were found to be related to the presence of [1¯10]-oriented misfit dislocations in 1-thick films which grew almost 2-dimensionally. In samples which exhibited mixed 2- and 3-dimensional growth characteristics, large domains (1 to 5 in width) in cathodoluminescence imaging of the ZnSe free-exciton emission were found to be correlated with a cellular pattern in the imaging of GaAs exciton and bandedge-to-acceptor emissions. The results showed that the optical properties of the ZnSe film and the GaAs substrate were coupled, and were affected by Zn diffusion into the substrate during growth.

H.T.Lin, D.H.Rich, D.B.Wittry: Journal of Applied Physics, 1994, 75[12], 8080-4