Design,Fabrication,and Characterization Of Thin-film Devices With Spectral And Photoelectric Responses

Spectroscopy is the technique of measuring light intensity in the ultraviolet,visible,near-infrared,and infrared bands.Spectroscopic instruments are the basic equipment for analyzing and measuring the composition and structure of substances using optical technology,electronic technology and computer technology.Due to the shortcomings of traditional spectrometers such as complex structure,limited use environment,inconvenient carrying,and high price,they cannot meet the needs of on-site detection and real-time monitoring.Therefore,micro-spectrometer and chip spectrometers have become an important direction for the development of spectroscopic instruments.Based on the law that the transmission center wavelength of the Fabry-Perot resonance cavity changes with the increase of the incident angle（angular drift effect）and the cavity thickness,the following works are carried out:1.A fiber grating wavelength demodulation system based on the"peak wavelength angle-dependent shift effect"of the filter was built:Take advantage of the peak wavelength angle-dependent shift effect of the optical filter.the incident light is preset to 0 and 5°at two narrowband filters.respectively,in the reflected wavelength range of the fiber grating,the transmitted light intensity of the two filters changes with the wavelength in the opposite trend.Then a fiber grating wavelength interrogating system was built with a wavelength demodulation accuracy of up to±5 pm.2.A thin-film device integrating spectral selection and photoelectric responses based on a linear gradient filter was designed and fabricated.First,two metal/dielectric/metal linear variable optical filters were prepared:（1）Si O₂（204.2nm）/Ag（35.0 nm）/Si O₂（127.0-307.0 nm）/Ag（35.0 nm）/Si O₂/（204.2 nm）.The filters exhibited a working spectral range of 500-1000 nm,a linear dispersion coefficient of about 16.7 nm/mm,a resonance transmission peak of about 35%,and a half-height and full width are 45.0 nm.（2）AZO（142.7 nm）/Ag（35.0 nm）/AZO（57.1-164.2 nm）/Ag（35.0 nm）/AZO/（71.4 nm）.The operating spectral range is 400-800 nm,the linear dispersion coefficient of about 13.3 nm/mm,the resonance transmission peak of about 60%,and the half-height full width of 30 nm.Secondly,n-type AZO films are prepared on p-type silicon wafers to form p-n junctions,which have wide-band photoelectric response.Furthermore,AZO（142.7 nm）/Ag（35.0 nm）/AZO（57.1-164.2 nm）/Ag（35nm）/AZO（71.7 nm）linear variable optical filters were prepared in the upper part to make the samples have different spectral-photoelectric responses at different positions.The spectral response at different locations on the sample was measured with a maximum photocurrent of 14 nA.