It was noted that the use of atomic H effectively cleaned GaAs substrates in readiness for the subsequent growth of ZnSe via molecular beam epitaxy. Optical fluorescence microscopy was shown to be a useful technique for imaging non-radiative defects that were related to stacking faults. It was found that, whereas the density of stacking faults in ZnSe films which had been grown using conventional thermal cleaning was greater than 107/cm2, stacking fault densities of less than 104/cm2 could be obtained by means of atomic H cleaning. The low-temperature photoluminescence spectra of undoped ZnSe were dominated by excitonic transitions, in the case of low defect-density samples. This contrasted with the high level of defect-related emission from high defect-density samples.

Z.Yu, S.L.Buczkowski, N.C.Giles, T.H.Myers: Applied Physics Letters, 1996, 69[1], 82-4