Investigations on electrical conduction properties and crystallization conditions of V 2 O 5 -P 2 O 5 glass based semiconductors

We studied the electrical properties of thermally treated V 2 O 5 -CuO-Fe 2 O 3 -P 2 O 5 (vanadate) glasses under reducing high-vacuum conditions. The glasses were prepared by using a melt-quenching method and then applied on Al 2 O 3 substrates as ∼40μm-thick films. The glass films were then heat treated at 375−550°C under a vacuum of 10 −6 Pa. Powder X-ray diffraction showed the formation of complex oxides of both M x V 2 O 5 (M = Cu, Fe; x = 0.12−1.3) and vanadium oxides (VO x ; x = 1.5−2.5). The resistivity of the glass film crystallized at 550°C measured at 50°C and 300°C were 1.8 × 10 0 Ωcm and 2.8 × 10 −1 Ωcm, respectively, which was 10 times lower than that of the film crystallized in air. The Seebeck coefficient was −132 μV/K at 50°C and −130 μV/K at 300°C. These results show that the vanadate glasses crystallized under the appropriate condition become potential candidate materials for semiconductor and thermoelectric application.