Humidity sensing properties of spray deposited Fe doped TiO_(2)thin film

In the present work,ferrite(Fe)doped TiO_(2)thin films with different volume percentage(vol%)were synthesized using a spray pyrolysis technique.The effect of Fe doping on structural properties such as crystallite size,texture coefficient,microstrain,dislocation densities etc.were evaluated from the X ray diffratometry(XRD)data.XRD data revealed a polycrystalline anatase TiO_(2)phase for sample synthesized up to 2 vol%and mixed anatase and rutile crystalline phase for sample synthesized at 4 vol%Fe doped TiO_(2).The crystalline size was observed to decrease with increase in Fe dopant vol%and also other structural parameters changes with Fe dopant percentage.In the present work,electrical resistance was observed to decrease with a rise in Fe dopant vol%and temperature of the sample.Thermal properties like temperature coefficient of resistance and activation energy also showed strong correlation with Fe dopant vol%.Humidity sensing properties of the synthesized sample altered with a change in Fe dopant vol%.In the present paper,maximum sensitivity of about 88.7%for the sample synthesized with 2 vol%Fe doped TiO_(2)and also the lowest response and recovery time of about 52 and 3 s were reported for the same sample.

Influence of precursor solution concentration on the structural, optical and humidity sensing properties of spray-deposited TiO_2 thin films

In the present paper,the influence of precursor concentration on the structural,optical,and humidity sensing properties of spray-deposited titanium dioxide(TiO) films are investigated. The TiOthin films were successfully deposited by spraying different precursor concentrations such as 0.075 M, 0.1 M, and 0.125 M of titanium trichloride solution onto glass substrates. X-ray diffractometry(XRD) studies confirmed the polycrystalline anatase phase of TiOwith dominant(101) plane. The crystallite size was found to increase with the increase in precursor concentration. The micro-strain and dislocation density in the film was observed to decrease as the crystallite size increased. The UV-vis spectra confirmed the optical absorbance edge of the samples shifted toward lower wavelengths with increased precursor concentration. The humidity sensing properties of the synthesized material were measured by monitoring the change in resistance of the sample with the change in relative humidity.The material synthesized with 0.1 M precursor concentration, by using the spray pyrolysis method,shows good sensitivity and has a response time of 77.5 s and fast recovery time of 3 s.

A simple chemical route to synthesize the umangite phase of copper selenide(Cu3Se2) thin film at room temperature

Copper selenide（Cu3Se2/thin films have been synthesized with Se as the precursor in aqueous solution by chemical bath deposition technique at room temperature.We have investigated the influence of the growth time ranging from 30 to 90 min on structural,optical and electrical properties of Cu3Se2 thin films.The as-grown film at 60 min exhibits a tetragonal structure and is（101）oriented.The maximum value of crystal size DD55 nm is attained for Cu3Se2 films grown at 60 min.The Raman spectrum reveals a pronounced peak at 259 cm 1,which is assigned to vibrational（stretching）modes from the covalent Se–Se bonds.The optical band gap energy is 1.91 to2.01 eV with growth time increased from 30 to 90 min.The scanning electron microscopy（SEM）study reveals that the grains are uniform and spread over the entire surface of the substrate of the film at 60 min.The Hall effect study reveals that the film exhibits p-type conductivity.The synthesized film showed good absorbance in the visible region which signifies that synthesized Cu3Se2 films can be suitable as a sensitized material in semiconductor sensitized solar cells.

Recent progress in emerging BiPO_(4)-based photocatalysts:Synthesis,properties,modification strategies,and photocatalytic applications

In this perspective,we have highlighted the current literature and explained the synthesis,structure,morphology,modification strategies,and photocatalytic applications of emerging BiPO_(4)-based photocatalysts.Since BiPO_(4)is a large bandgap photocatalyst,it uses UV light for the excitation of electrons,and also,the recombination of charge carriers is an issue in BiPO_(4).Various novel modification strategies of BiPO_(4)photocatalysts viz.defect modifications,heterojunction formation,phase-junctions,surface plasmon resonance,Schottky junction have been successfully proposed and highlighted.These modifications enhance the light absorption and inhibit the recombination of charge carriers BiPO_(4)photocatalyst.Finally,future aspects for further research on BiPO_(4)-based photocatalysts are also explored.It expects that BiPO_(4)-based photocatalysts represent a promising strategy for developing practical photocatalysts for energy and environmental remediation applications.