Research On The Preparation Technology And Performance Of GaAs Based Nuclear Radiation Detector

Since the development of Gallium arsenide（GaAs）nuclear radiation detector in the1970s,the detector has good preparation technology and detection performance,but the research on the radiation hardness,radiation damage repair and low power consumption of GaAs detector is very few,and the application of some special environments puts forward higher requirements for the detector performance,which has become a constraint to its further development impede.In this paper,the preparation and characterization of GaAs based nuclear radiation detector,radiation hardness,radiation damage repair and other aspects were studied.A semi-insulating GaAs schottky type detector is designed and fabricated,and its electrical characteristics are tested.When the bias voltage is–100 V,the leakage current of the device is 7.83 n A,and the current density is 2.51×10^-7 A/cm²,the barrier height of the detector is 0.93 e V,and the energy spectrum ofαparticle(²⁴¹Am,5.48 Me V)and charge collection efficiency（CCE）of the detector are tested.When the reverse bias is 20 V,the energy resolution of the detector reaches 8.3%,and when the reverse bias is 60V,the CCE reaches 80%.The irradiation hardness of semi-insulating GaAs detector was studied by using 10 Me V high energy electron irradiation with a cumulative dose of 0～200 k Gy.The performance of the detector after irradiation was characterized by current-voltage（I-V）,CCE andαparticle energy spectrum.After irradiation,the energy resolution and CCE of the detector decrease,but the detection efficiency was improved.The detector can still detect after high dose irradiation.After irradiation,the semi-insulating GaAs Schottky detector was annealed to study the repair of irradiation damage.The I-V,αenergy spectrum and CCE of the annealed device after irradiation were measured and analyzed.The test results show that thermal annealing can partially repair the damage caused by electron irradiation.For the first time,a new type of pin type nuclear radiation detector with variable component and variable doping of Al GaAs/GaAs has been prepared,and its electrical characteristics andαparticle energy spectrum have been tested for different size detectors.The test results show that the detector has high sensitivity and can work under zero bias voltage,with energy resolution of 3.3%under zero bias voltage.⁵⁵Fe（5.9 ke V）X-ray source was used to test the X-ray detection performance of Al GaAs/GaAs pin type nuclear radiation detector.The detector has an obvious detection response to X-ray,but it can only observe a single signal response through oscilloscope,and can not test multi-channel energy spectrum.On the one hand,the device structure needs to be optimized,and the leakage current is too large.On the other hand,the energy of ⁵⁵Fe（5.9 ke V）X-ray source is low.