HIRFL-CSR外靶终端上硅微条探测器阵列的搭建

硅微条探测器因具有很强的位置分辨率与能量分辨率而在世界各大核物理实验室得到广泛应用。中国科学院近代物理研究所研制了性能优越、位置精度达到0.5 mm×0.5 mm的双面硅微条探测器,用于HIRFL-CSR的外靶实验终端谱仪(ETF)上,用作径迹测量以及△E-E望远镜系统△E的探测。硅微条探测器体积小、集成度高,利用柔性印刷电路板(FPCB)引出信号,配合ASIC芯片的前端电路,能够方便地给出每一条的能量信息和位置信息。在此详细阐述了在HIRFL-CSR的ETF上双面硅微条探测器阵列的搭建,并测量了放射源在真空中探测单元的能量分辨本领。结果表明,该硅条探测器的每个探测单元对5~9 MeV能量的α粒子的能量分辨率在1%左右。     

Na-Mg共掺杂ZnO薄膜的结构和光学性质

利用溶胶-凝胶法,在普通载玻片上使用旋转涂膜技术制备了具有c轴择优取向生长的Na-Mg共掺杂的ZnO薄膜。用XRD、SEM、光致发光(PL)及透射光谱对薄膜样品进行了表征。结果表明:Na-Mg共掺杂有利于ZnO薄膜的c轴择优取向生长,并且随着Na+掺杂浓度的增加,晶粒尺寸先增大后减小;通过比较不同掺杂浓度ZnO薄膜的PL谱,推测发光峰值位于380nm的紫外发射与ZnO的自由激子复合有关;发现掺入Mg的确能使ZnO禁带宽度增大,掺杂组分为Na0.04Mg0.2Zn0.76O时,其PL谱只有一个很强的紫光发射峰,其近带边紫外光发射强度较未掺杂的ZnO增强了近10倍,极大地提高了薄膜紫外发光性能;并且随Na+浓度增加薄膜透光性减弱。     

Phonon contribution to nonionizing energy loss in silicon detectors

Nonionizing energy loss (NIEL) has been applied to a number of studies concerning displacement damage effects in materials and devices. However, most studies consider only the contribution of displacement damage effects, neglecting the contribution from phonons. In this paper, a NIEL model, which considers the contribution of phonons, has been established using the Monte Carlo code SRIM. The maximum endurable fluence for silicon detectors has been estimated using the equivalent irradiation fluence compared with experimental data for the incident particles. NIEL is proportional to the equivalent irradiation fluence that the detector has received.     

Application of stratified implantation for silicon micro-strip detectors

In the fabrication of a 48 mm×48 mm silicon micro-strip nuclear radiation detector with 96 strips on each side, a perfect P-N junction cannot be formed consistently by the one-step implantation process, and thus over 50% of strips produced do not meet application requirements. However, the method of stratified implantation not only avoids the P region between the surface of wafers and the P⁺ region, but also overcomes the shadow effect. With the help of the stratified implantation process, a perfect functional P-N junction can be formed, and over 95% of strips meet application requirements.     

ZnO 紫外探测器的研究

利用水热法生长的N型优质ZnO晶体材料蒸镀了Au、Ag、Al金属,制备出金属-半导体-金属型(MSM)ZnO紫外探测器,测试了五种接触类型的ZnO紫外探测器(Au-ZnO-Au、Ag-ZnO-Ag、Au-ZnO-Al、Ag-ZnO-Al、Al-ZnO-Al)在365nm紫外光光照前后的I-V特性曲线。实验表明Au-ZnO-Au 型、Ag-ZnO-Ag型的探测器的光电流是暗电流的100 万倍,因此,Au-ZnO-Au型、Ag-ZnO-Ag型的ZnO紫外探测器性能比Au-ZnO-Al、Ag-ZnO-Al、Al-ZnO-Al型的优越。ZnO材料的电阻率对ZnO紫外探测器的光电流有较大的影响。在相同偏压下,电阻率越大,探测器的光电流越小。ZnO ultraviolet(UV) detectors with Metal-Semiconductor-Metal(MSM) structure were fabricated by the vacuum evaporation of Au, Ag, and Al on the n-type ZnO single crystal, which was grown with hydrothermal synthesis method. Five types of MSM ZnO detectors(Au-ZnO-Au, Ag-ZnO-Ag, Au-ZnO-Al, Ag-ZnO-Al,Al-ZnO-Al) were illuminated with 365 nm UV light respectively, and their corresponding I-V(Current-Voltage) characteristics were measured. The UV photocurrent values for Au-ZnO-Au and Ag-ZnO-Ag detectors were 1x106 times than their dark current values, and these facts imply that the Au-ZnO-Au and Ag-ZnO-Ag detectors were rather good UV detectors compared to Au-ZnO-Al, Ag-ZnO-Al, Al-ZnO-Al detectors. The photocurrent of the MSM ZnO detectors was also sensitive to the cubic resistance of the ZnO crystal. And it’s found that the higher resistance rate the ZnO crystal the smaller photocurrent value the detector under the same working voltage.