The fabrication of semiconductor imaging arrays with optimum spectroscopic capabilities requires the parallel development of modelling techniques to investigate the effects of carrier transport on detector performance. We have developed an analytical approach based on the method of weighting potentials. It is found that diffusion may cause substantial deterioration of array characteristics by distorting carrier motion in the crucial near-field region. As a result, not only are the imaging characteristics of the array impaired, but, also, its spectroscopic performance may be greatly degraded.