In this paper, we present calculations for different parameters of quantum dot infrared photodetectors. We considered a structure which includes quantum dots with large conduction-band-offset materials (GaN/AlGaN). Single band effective mass approximation has been applied in order to calculate the electronic structure. Throughout the modeling, we tried to consider the limiting factors which decline high temperature performance of these devices. Temperature dependent behavior of the responsivity and dark current were presented and discussed for different applied electric fields. Specific detectivity used as figure of merit, and its peak was calculated in different temperatures. This paper indicates the state of the art in the use of the novel III-N materials in infrared detectors, with their special properties such as spontaneous and piezoelectric polarizations. It was found that, III- nitride Quantum dots have a good potential to depress the thermal effects in the dark current which yields the specific detectivity up to~ 2107 CmHz 1/ 2/W at room temperature.