Studies on nanostructured V2O5/V/V2O5 films for un-cooled IR detector application

• Published in: Journal of materials science. Materials in electronics Vol. 27; no. 7; pp. 7494 - 7500
• Main Authors: Deepak Raj, P., Gupta, Sudha, Sridharan, M.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.07.2016
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Optical and Electronic Materials; Oxygen Partial Pressure; Sheet Resistance; V2O5; Multilayer Film; Vanadium
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-016-4727-7

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