Study On Ga₂O₃ UV Conductance Detection And Read Out Circuit

Working in the solar blind?200²80nm?UV photoconductive sensors are not easily disturbed by the natural environment and can still be detected by the sunlight environment.It has low false alarm rate and unique detection advantages.It has wide application value in the military and civil fields such as cosmic exploration,missile tracking,fire warning and so on.A?-Ga₂O₃ thin-film photoconductive sensor.which is easily obtained for metal oxides,and can be prepared by agnetron sputtering or molecular beam epitaxy.It has simple preparation process,low cost,and the forbidden band gap of 4.9 eV.It can work in the blind band without doping,and the detection background is extremely clean.It is the ideal material for the preparation of solar blind UV detection.However,the photoconductive response time is longer and in the second order of magnitude,its performance conditions are required to further studies.At present,the research on?-Ga₂O₃ photoconductive detection is limited to the probe bench test environment,and the response performance cannot be fully embodied in the specific circuit application,and further testing is needed.Probes have found that the probe station can detect extremely small photocurrents,but for specific circuit detection,the detection precision and the dynamic range constraints of the resistance feedback detection circuit make it difficult to detect the weak light,and the detection circuit should be optimized.The Ga₂O₃ photoconductive detection and imaging array has almost no specific application in China.It is of great significance to research the optimized imaging circuit for imaging applications.In order to study the response of the gallium oxide photoconductive detector in specific circuit,this paper prepares?-Ga₂O₃ thin film structure photoconductive detectors,tests the partial photoresponse performance of the device under different annealing conditions,encapsulates the detector device,and designs the test circuit.builds test environment to test the photoelectric detection performance of its package and study the application performance of the photoconductive detector in the detection.The I-V characteristic test of the?-Ga₂O₃ photoconductivity detector shows that the dark current is in the order of pA and the light dark current ratio is above 60dB;the response test results show that the response degree is higher than that of 3A/W and has a greater advantage than the SiC diode;the peak value of the spectral response is in254nm,and the response ratio of the peak to the non-solar blind band is up to 10⁴,spectral detection selectivity is excellent;the response time test found that the rise and fall of the sensor response time is in the order of seconds,which restricts its application in imaging array.In order to further apply photoconductive detectors to imaging arrays,the effect of different conditions on the response time of the device is tested by controlling the change of the film quality,the width of the interdigital,the bias voltage and the stress.In view of the problems of small current detection,low precision and large output noise in the feedback resistance detection circuit,an improved circuit applied to imaging is proposed so that it has stronger detection ability for weak current signal and more stable detection circuit.By building a 4×4 pixel array,the performance of the optimized detection circuit in the imaging application is verified by simulation.This paper is of great significance to the research of ultraviolet conductance detection and the design of detection circuit.It not only studies the response characteristics of ultraviolet conductance detection and the influence factors of time response,but also provides a practical basis for improving the performance of the detector,and has a certain reference value for the improvement of the detector and the realization of the imaging array.