The Hall and photo-Hall effect were studied in pure or doped n-type ZnSe epilayers which had been grown, via molecular beam epitaxy, onto semi-insulating GaAs substrates. An anomalous depression of the dark values of the room-temperature and peak mobility in the ZnSe layer was observed in many samples, while normal values of mobility were found under illumination with above-bandgap light. This was associated with an increase in the effective areal electron density. These results suggested that space-charge scattering caused the dark mobility reduction. The photo-Hall effect in heterostructures was considered in terms of simple models which contained both misfit dislocations at the heterostructure interface, and extended defects in the bulk of the ZnSe epilayer.

H.Van Houten, S.Colak, T.Marshall, D.A.Cammack: Journal of Applied Physics, 1989, 66[7], 3047-55