Short-wave Infrared Line Array Imaging Circuits And System Design For Colloidal Quantum Dots

Due to excellent concealment,environmental adaptability and anti-interference ability,shortwave infrared(SWIR)imaging technology has shown important values in military,medical,transportation,industry,agriculture and other fileds.The commercial In Ga As photodetectors occupy the major market in SWIR photodetection at high cost and by complicated process,limiting its application development severely.Herein,Pb S colloidal quantum dots(CQDs)demonstrate many advantages,such as low cost,high compatibility with CMOS,adjustable response band,high sensitivity,high fill factor and etc.CQDs are very likely to become the next generation of SWIR photosensitive materials.However,Pb S CQDs based imaging technology has not been sufficiently studied.It is very important to investigate its imaging feasibility,imaging method,imaging circuit and system.In this paper,a line array imaging circuit and system was designed for further research of Pb S CQDs with high portability,good iterability,low cost,short fabrication cycle and intuitive display.Firstly,the basic performance and process requirements of Pb S CQDs photodetector was analysed in detail.A line array of Pb S CQDs photodetectors was manufactured and heterogeneously integrated with readout circuit,converting optical signal to photo-generated current.Secondly,a front-end detection circuit was designed based on chip AFE0064 through comparing the characteristics of several common input circuits,converting photo-generated current to analog voltage.Thirdly,the output characteristics of the front-end detection circuit was considered such as frequency,accuracy and amplitude of analog voltage.The analog-to-digital converter(ADC)module was designed based on chip ADS8363 to convert analog voltage to digital signal.Fourthly,the drive signal protocol was connected to a screen by the HDMI interface,and the output rate and encoding method were further studied.The data processing module was designed based on FPGA to convert the digital signal into driving signal of the screen.Finally,the screen displayed completely the line array imaging and real-time display assisted by the displacement platform.The successful imaging experiments prove that the designed line array imaging circuit and system in this thesis can realize the imaging function for Pb S CQDs.The line array imager shows a response band of 0.76 ? 1.3 ?m,a frame rate of 60 fps,a pixel array of 1×64,and a dynamic range of 51.32 d B.This provides a low-cost and convenient reference method for future research and development of Pb S CQDs and other photosensitive materials.