This paper presents the recent developments of device models for quantum dot IR photodetectors (QDIPs) and for imagers based on the integration of these photodetectors with light emitting diodes (LEDs). We derive analytical formulas for the dark current and the responsivity in QDIPs based on different QD structures and the QDIP-LED contrast transfer characteristic as functions of the structural parameters and the bias voltage. It is shown that the characteristics of QDIPs are strongly affected by the effect of electron accumulation in QDs close to the emitter contact. The main effect limiting QDIP-LED imager resolution is associated with the processes of photon reabsorption and reemission in the device LED part.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.