Hardening and Optimizing of the Black Gold Thin Film as the Absorption Layer for Infrared Detector

This paper reports on the study of the black gold thin film as the absorption layer in the near infrared spectrum. The fabrication of the black gold thin film was achieved by a thermal evaporation technique in N2 atmosphere. Different evaporation conditions were attempted to optimize the absorbance of the black gold coating, especially the atmosphere pressure and the mass of evaporation source. The long-standing problem of black gold’s adhesion with the substrate was solved by fuming 502 superglues into the black gold layer, which had almost no impact on the absorbance performance. Layers produced at N2 atmosphere of 3×103 Pa show an absorbance exceeding0.9 inthe near infrared.

Morphology enhancement of SiO_(2)aerogel films grown on Si substrate using dense SiO_(2)buffer layer

Porous SiO_(2)film has been widely studied due to its extensive applications in many fields.This paper presents a newly produced porous SiO_(2)film made by traditional sol-gel method.Bare Si and Si with SiO_(2)buffer layer were used as substrate.The SiO_(2)buffer layer was 500 nm in thickness and was grown by thermal oxidization.The structural properties of SiO_(2)aerogel films spincoated on both materials were observed by optical microscope(OM)and scanning electron microscope(SEM).Results reveal that the surface of SiO_(2)aerogel films on bare Si is rough and discontinuous.While flat and smooth surface is observed on sample with SiO_(2)buffer layer.This indicates that by inserting SiO_(2)buffer layer,the structural property of SiO_(2)aerogel film deposited on Si is improved.

Highly precise Ti/Pt/Cr/Au thin-film temperature sensor embedded in a microfluidic device

A multilayer(Ti/Pt/Cr/Au)resistive temperature sensor was proposed and investigated to precisely measure the temperature characteristic in microfluidic devices.The Ti/Pt/Cr/Au sensor was fabricated by direct current(DC)sputtering,vacuum evaporation and liftoff process.The thermal annealing test was conducted in the temperature range of 200-800℃for obtaining an appropriate property of the multilayer.Based on the experimental results,400℃was selected as the experimental annealing temperature for the Ti/Pt/Cr/Au layer.The redistribution of structural imperfections and recrystallization promote the density and adhesion of multilayer during the annealing process.With the annealing temperature rising,the annealing process leads to through-thickness migration of chromium and partial depletion of the adhesive layer.The Ti also diffuses into the Pt,which makes the interface disappear.Nevertheless,the layer remains continuous.The temperature coefficient of resistance(TCR)of the sensors was investigated through the microfluidic testing system.The excellent stability and sensitivity of the Ti/Pt/Cr/Au thin-film temperature sensor are verified.Furthermore,the capability of the Ti/Pt/Cr/Au thin-film temperature sensor detecting the sudden temperature change caused by bubble effect is very meaningful to the microfluidic devices.

Enhanced pyroelectric properties of PZT/PVDF-TrFE composites using calcined PZT ceramic powders

The effects of calcined lead--zirconate-titanate(PZT)powders on the electric properties of PZT/polyvinylidene-tifluorethylene copolymer(PVDF-TrFE)composites thick films were studied in this paper.Firstly,the PZT powders synthesized by hydrothermal method were calcined at different temperatures ranging from 300℃ to 900℃,and then the PZT/PVDF-TrFE composites films were produced by casting PZT/PVDF-TrFE suspension onto the indium-tin-oxide(ITO)-coated glass substrates.Electric properties,including dielectric and pyroelectric performances of thick films consisting of PZT powders calcined at different temperatures were tested.The highest pyroelectric cofficient obtained in the sample using 700℃ calcined PZT powders was 96μCm^(-2)K^(-1),which was 20%higher than the composites made of uncalcined powders.Additionally,the highest detectivity figure-of merit(FOM)(FD)of the composite was 1.36×10^(-5)Pa^(-1/2),which increased about 13.5%compared to the one using uncalcined powders.