Fabrication Of Cadimum Selenide(CdSe)Room Temperature Nuclear Radiation Detector

Due to it's wide energy gap (Eg=1.7eV)Jiigh atom number(41) and high density(?=5.74g/cm3), Cadimum Selenide(CdSe) is regarded as one of the most promising materials for room temperature nuclear radiation detectors.It is widely used in many fields espescially at photoelectric instruments.In this paper, the technique of fabricating CdSe detectors was studied.Two typies of CdSe detectors were fabricated: one has metal-semiconductor-metal (MSM) strructure and the other has metal-insulator-semiconductor contacts (MIS). The MSM detector has larger leakage current of about 10-9A(300V), and it's energy resolution for 241Am 59.5Kev line is 40%; the MIS detector has lower leakage current of about 10-12A(300V),and it's energy resolution for 241Am 59.5Kev line is up to 10%. Leakage current is one of key factors for the energy resolution of the detectors, the MIS detector has lower leakage current thus improve the energy resolution. The MIS structure is a good contact type for the CdSe detectors.By the analysis of the mechanism of charge carries transporting in the detector and the polarization effect of MSM detector, we get: The polarization effect of CdSe detectors is mainly caused by the poor transporting of charge carries;To avoid the polarzation effect and improve the charge carries transporting property,the detector must has a suitable anode,so as to make a more suitable electrical field.We have obtained some achivements in this work, and our work is one of the important progress in the field of the CdSe room temperature nuclear detector research.