Studies on nanostructured V sub(2)O sub(5)/V/V sub(2)O sub(5) films for un-cooled IR detector application

Sensitive micro-bolometer devices require a sensor layer of high temperature coefficient of resistance (TCR) value with low resistance to reduce noise. Since it is difficult to produce vanadium pentoxide (V sub(2)O sub(5)) with high TCR and low resistance values, a sandwich type architecture approach was chosen, in which V sub(2)O sub(5)/V/V sub(2)O sub(5) structure was formed using reactive direct current magnetron sputtering technique by varying the argon (Ar) and oxygen (O sub(2)) ratio. On increasing the O sub(2) partial pressure, an increase in the crystallinity of the V sub(2)O sub(5) film was observed using X-ray diffraction (XRD) studies, which was due to the availability of abundant oxygen to form V sub(2)O sub(5). X-ray photoelectron spectroscopy (XPS) result of V sub(2)O sub(5)/V/V sub(2)O sub(5) indicated a decrease in V2p peak and increase in O1s peak, confirmed the multilayer had mixed vanadium oxide phases of V super(3+) and V super(2+) oxides of vanadium due to the diffusion of oxygen from top and bottom V sub(2)O sub(5) layer into the V metal layer. V sub(2)O sub(5)/V/V sub(2)O sub(5) multilayer films at the higher O sub(2) ratio had TCR value -2.5 %/ degree C with a resistivity of 19 Omega /cm super(-1), which is compatible for un-cooled IR detector application.