A new multi-function thin-film microsensor based on Ba_1-xLa_xTiO₃

Abstract

A new multi-function microsensor with a barium lanthanum titanate (Ba1-xLaxTiO3) thin film is developed for the fabrication of a thin-film resistor and a metal-insulator-semiconductor (MIS) capacitor on a SiO2/Si substrate. The results reveal that the thin-film resistor has good sensitivity to visible light and good thermal sensitivity within the temperature range of 28-400 °C. The MIS capacitor is sensitive to changes in the relative humidity (RH), with a 130% change of the current for a humidity change from 12 to 92% RH at a test frequency of 500 Hz, and with short response times of 5 and 4.5 s for the adsorption and desorption of water vapor, respectively. The effects of the test frequency on the photo, thermal and humidity sensitivity performances are also investigated. Since the lifetime of charge carriers of Ba1-xLaxTiO3 thin films is only 16 ms, about half that of Sr1-xLaxTiO3 thin films, the device can detect light modulation at higher frequencies.

Synthesis, structure and electrical behaviour of nickel-doped barium stannate

“…Their electrical properties and hence sensing behavior can be modified easily by an appropriate substitution of cations at A and B sites of the oxide ABO 3 . At present thin and thick film of these oxides are being used for fabrication of multifunctional sensor [1][2][3]. Alkaline-earth stannates (ASnO 3 , where A = Ca, Sr, Ba) are also members of perovskite oxide family.…”

Sensing Properties of Ba1划xLaxNbyTi1划yO3 (x=0.25%, y=0.25%) Thin-Film on SiO2/Si Substrate

“…Figure 4 exhibit a negative temperature coefficient (NTC) and have good linearity and high sensitivity. The temperature coefficient of the film at 30 o C is -5.22% o C -1 under a test voltage of 1 V, which is similar to that of SrNb x Ti 1-x O 3 film (-4.36% o C -1 ) [1], and higher than that of Ba 1-x La x TiO 3 (-1.61% o C -1 ) [2] and Sr 1-x La x TiO 3 (-1.73% o C -1 ) [6]. The effect of test frequency on the impedance (Z) of the film resistor at different temperatures is depicted in Figure 5.…”

“…Perovskite-type oxides (ABO 3 ) attract much attention in recent years because these oxide are not only used as high-permittivity dielectric in non-volatile memory, but also can be used as sensing materials, moreover, sensing properties of these oxides may be modified by appropriate combination of cationic constituents. Our previous works [1,2] have found that even though both Ba 1-x La x TiO 3 and SrNb x Ti 1-x O 3 thin film have photo-, thermal and humidity sensitivity characteristics, photo sensing characteristics is better in La-doped film and thermal sensing characteristics is better in Nb-doped film. Therefore, in this work, Ba 1-x La x Nb y Ti 1-y O 3 (x=0.25%, y=0.25%) thin-film is proposed with a view to achieving better photo, thermal and humidity sensing properties.…”

Effects of annealing conditions on photoelectrical properties of Ba1−xSrxNbyTi1−yO3thin-film resistor

“…SrNb x Ti 1−x O 3 and Ba 1−x La x O 3 thin films have demonstrated good sensitivity to visible light [6,7]. In this work, Ba 1−x Sr x Nb y Ti 1−y O 3 thin film is developed for the fabrication of thin-film resistors on SiO 2 /Si substrate to achieve supe-rior photosensing properties within a wide optical wavelength range.…”