Research On CCD Ultraviolet Enhancement Technology And Performance Test

The CCD photodetector is a silicon-based multi-channel array detector and as one of the core components of the micro spectrometer,it has the advantages of small size,light weight,fast response,and high imaging quality.However,the CCD silicon substrate polysilicon electrode has strong absorption of ultraviolet(UV)light,so the incident ultraviolet light basically cannot pass through the silicon substrate,so that it cannot be detected and the CCD will not respond.Therefore,it is a research direction for researchers at home and abroad to improve the response of CCD in the ultraviolet band.This article conducts in-depth research on the problem of insufficient CCD response capability in the ultraviolet and deep ultraviolet regions.The details are as follows:Firstly,this paper analyzes the structure,working principle,basic characteristics and current development status of CCD sensor in detail,and discusses the traditional method of enhancing the UV response capability of CCD's.It has been found that the general UV-enhanced method is to deposit fluorescent material on the CCD surface protection glass(Namely,Glass Window),and there is distance between the protective glass and the photosensitive surface,the scattering and reflection will weaken the incident light intensity,resulting in lower quantum efficiency,therefore research on window removal technology of CCD.The results of study show that the laser cutting method is a good window removal method,which can quickly and effectively remove the CCD protection glass under the premise of minimal damage to the CCD device,and lay a foundation for the research of CCD ultraviolet enhancement technology.Secondly,a study is conducted to enhance the UV response capability of the CCD.Lumogen Yellow S 0795 phosphor is selected as the film material according to the requirements.Since the CCD is a relatively expensive device,the thermal evaporation method is used to prepare the film sample on the glass substrate first to obtain the optimal film,and then the experiment is performed on the CCD photosurface,which can reduce costs and increase efficiency.The experimental results show that when the vacuum degree is 8×10-4 Pa and the evaporation current is 50A,the Lumogen material has good film forming effect,and the film layer is uniform and smooth and is not easily separated.Finally,the UV-enhanced CCD is mounted on a miniature spectrometer to perform performance testing.A low-pressure mercury lamp and a xenon lamp are selected as the light source to measure the UV discrete spectral response and the UV continuous spectral response of the CCD.The results show that the Lumogen fluorescence film can greatly improve the spectral response of the CCD in the ultraviolet region below 400 nm,enabling the ordinary front-illuminated CCD to respond in the deep ultraviolet region.and its response capability in the 365.01 nm spectral line is increased to 2.6 times or more.The spectral intensity at the 253.65 nm spectral line is even saturated after the coating,and the cutoff response wavelength also shifts from 306nm to about 235nm,and does not affect the permeability of visible light above 400nm.