Experimental And Simulation Study On Irradiation Effect Of Optocoupler

Optocoupler is a kind of electronic component which is composed of light-emitting diode and phototransistor.One of its most important roles is used to be an electric-opto-electric conversion device.As an important component of spacecraft signal transmission system,the problems that optocouplers suffered from space radiation damage have been paid more and more attention.In order to understand and analyze the damage mechanism and performance degradation of optocouplers in radiation environment and aim at the shortcomings of existing research,a variety of optocouplers are taken as the research object to carry out proton and neutron irradiation experiments in this paper.For the first time in China,the experiments of optocoupler irradiated by spallation neutrons have been carried out in the spallation neutron source which is located in Dongguan City.At the same time,the simulation of irradiation effect is carried out in this paper.Based on the combination of experimental research and simulation research,the radiation damage mechanisms of optocouplers are analyzed.The experimental results show that the radiation effects induced by proton and neutron can both lead to performance degradation of the optocoupler.In all parameters of the optocoupler,the current transfer ratio of the optocoupler,the luminous power of the light-emitting diode,the base current of and the output characteristic curve of phototransistor are the main radiation sensitive parameters.With the accumulated fluences increasing,the current transfer ratio of the photocoupler decreases obviously,and the peak also shifts.As a part of optocoupler,the luminous power of LED will decrease obviously with the accumulated fluences increasing.At the same time,with the increase of irradiation dose,the base current and the output characteristic curve of phototransistor will also degrade.For different energy protons,the irradiation damage of 60 Me V protons to photocouplers is more serious than that of 90 Me V protons.In this paper,TCAD is used to simulate the radiation effect on optocoupler,and the physical model of the optocoupler is built.At the same time,the corresponding radiation model is built according to the radiation particles.By using simulation software and experimental model,the radiation sensitive parameters such as I-V characteristic curve of light-emitting diode,light power of light-emitting diode andoutput characteristic curve of phototransistor are simulated and calculated.The simulation results and experimental results are verified each other.At the same time,the changes of the microscopic parameters such as current density distribution and carrier recombination rate of LED before and after irradiation are simulated,and then the results are analyzed.The simulation results provide a theoretical basis for the analysis of radiation damage mechanism of optocoupler.In this paper,the damage mechanism of optocoupler radiation effect is further studied by combining the experimental and theoretical simulation research,which provides theoretical basis and experimental technical support for the research of radiation hardening technology of optocoupler.