Solar Blind Ultraviolet Imaging Device Based On A Composite Structure Containing One-dimensional Photonic Crystal And Quantum Dots

When the sunlight passes through the atmosphere, the solar-blindultraviolet light almost been absorbed, so the application of solar-blindultraviolet light imaging can avoid the disturbances from the sunlight, andit has been widely applied in the detection of high pressure discharge,criminal investigation, ultraviolet missile warning and so on. Photoniccrystal is an artificial material which is form from cycling configurationdielectric material in the space. It can achieve the selective hightransmission of light by photonic band gap and photon localizationproperties. Meanwhile, quantum dots are small size measurementnanomaterials with unique optical and electrical properties. Thesolar-blind ultraviolet light imaging device based on photonic crystalfilter and spectral conversion characteristics of quantum dots is small insize, imaging resolution getting improved, and addressing the problem of the filter in low yield and easy to aging, which provide a new way tosolve the photodetectors in the future.Currently, solar-blind ultraviolet imaging devices mainly exist thefollowing problems:(1) Based on the image intensifier by light-electricity-light conversion realizes ultraviolet imaging, the size ofimage intensifier reaches to10cm grade which is limiting deviceintegration; The imaging resolution is limited by the number of opticalfiber cone; Electron multiplication needs additional around1000V highvoltage transient.(2) Existing installations filters mainly adoptmembrane system design based solar blind ultraviolet filter or black uviolglass filter, with low yield and easy to aging.To slove the above problems, the research content and results ofthis paper can be summarized as:(1) Combining one-dimensional photonic crystal and quantum dotsphotoluminescence properties, and based on the transfer matrix method,to work out a quantum dot specyrum converter,. The structure canconverts solar-blind ultraviolet into visible light near610nm. Due to itsthickness is only about1nm and its size match the CMOS, the size of thedevice can greatly reduced. Besides, the conversion can be realizedwithout additional high-voltage power. Quantum dots have good stabilityand instantaneous light with high efficiency, so it can satisfy therequirement of imaging. (2)The solar-blind ultraviolet imaging device consists of ultravioletimaging lens, quantum dots spectrum converter, COMS, imageacquisition, data processor and screen. Though the device size is small, itcan accommodate104quantum dots witnin a single pixel size, and thelight of a single quantum dot can be perceived by CCD. The resolutioncan further improve with the reduction of pixel’s size. What’s more, thereis no need to install filter before spectrum converter.(3)By analysis the effect of temperature and incident light changingon imaging resolution, we find that whether temperature changing from25℃~50℃, or incident light changing from0o~30o, the blind ultravioletdevice can realize high resolution.