The influence of inhomogeneous trap distribution on results of DLTS study

A model is developed to describe how a narrow distribution of deep traps adjacent to quantum dots (QDs) influences the trap-related signals measured by frequency scanned deep level transient spectroscopy (FS-DLTS). By comparison with experiment, it is demonstrated that traps with a steep concentration gradient, positioned in the so called transition layer close to the edge of the depletion region ("lambda-effect"), have a strong influence on DLTS signal amplitudes. This is manifested by an extreme sensitivity to the change in the Fermi-level position when temperature is varied