Material considerations for current and next generation microbolometer technology

Electrical conduction in materials used in microbolometer technology, such as vanadium oxide (VOx) and amorphous silicon (a-Si), is via carrier hopping between localized states. The hopping conduction parameters determine the temperature coefficient of resistance (TCR), its temperature dependence, and its relationship to resistivity. The electrical noise has a 1/f component that is also associated to the hopping parameters and thus correlated to TCR. Current research on conduction in cross linked metal nanoparticles organized in an insulating matrix shows that TCR and noise can be controlled independently, potentially allowing for precise tailoring of the detector response for differing applications.