A study was made of the effect of misfit dislocations upon hole accumulation in the base-layer of a heterojunction photo-transistor. Spatial and temporal cathodoluminescence measurements revealed that variations in hole accumulation were caused mainly by strain-induced defects which impeded the transport of holes. The lifetime of holes in the InGaAs/GaAs collector was found to be negligibly affected by the underlying misfit dislocations in the collector. The reduction in local electron-beam induced currents, that was caused by dislocations, was less than 20%.

H.T.Lin, D.H.Rich, O.Sjölund, M.Ghisoni, A.Larsson: Applied Physics Letters, 1996, 69[11], 1602-4