一种国产GaInP/GaAs/Ge三结太阳电池的电子辐照特性

对一种国产GaInP/GaAs/Ge三结太阳电池进行了1 MeV电子辐照损伤研究,分析和讨论了不同注量电池电参数和光谱响应的衰降规律.实验结果表明,这种电池不但有很高的初始效率,而且有好的抗辐射性,电子注量达到1×1015 cm-2时,最大输出功率为辐照前的80.4%.辐照后GaInP顶电池几乎不发生退化,而GaAs中间电池短路电流严重退化,致使GaInP顶电池与GaAs中间电池电流失配,是GaInP/GaAs/Ge电池性能退化的主要原因.     

50-170 keV质子照射对GaAs/Ge太阳能电池光谱响应的影响

用固定能量(100 keV)不同注量(1×1011-3×1012 cm-2)或固定注量(3×1012 cm-2)不同能量(50-170 keV)的质子,照射GaAs/Ge太阳电池,获得材料的光谱响应特性随质子能量和注量的变化关系.结果表明,质子辐照对材料的光学性能有破坏性的影响.这种破坏性源于质子辐照引入的大量缺陷,使晶格空间的完整性受到破坏,导致少子的扩散长度降低、表面复合速度增加.在质子能量相同的条件下,电池光学性能衰降随照射注量增大;在注量相同的条件下,辐射能量越高,太阳电池光学性能衰降越大.     

位移损伤效应对AlGaN/GaN HEMT器件的影响

对AlGaN/GaN高电子迁移率晶体管(HEMT)分别进行3 MeV质子辐照和14 MeV中子辐照实验。3 MeV质子辐照下累积注量达到1×10¹⁵ cm^-2或14 MeV中子辐照下累积注量达到2×10¹³ cm^-2时，AlGaN/GaN HEMTs饱和漏电流下降，阈值电压正向漂移，峰值跨导降低。分别对3 MeV质子辐照和14 MeV中子辐照后的AlGaN/GaN HEMTs进行深能级瞬态谱(DLTS)测试。3 MeV质子辐照后缺陷浓度下降降低了反向栅极漏电流，而14 MeV中子辐照会导致缺陷浓度增加，使得反向栅极漏电流增加。根据质子和中子辐照后的缺陷能级均为(0.850±0.020) eV,推断缺陷类型均为氮间隙缺陷，质子辐照和中子辐照后氮间隙缺陷的位移导致的位移损伤效应是AlGaN/GaN HEMT器件电学性能退化的主要原因。     

柔性倒置赝型三结太阳电池高能质子辐射效应研究

为考察柔性薄膜GaInP/GaAs/InGaAs倒赝型三结（IMM3J）太阳电池的抗辐照性能,本文对其进行了1、3、5 MeV高能质子辐照。SRIM模拟结果表明,1、3、5 MeV质子辐照在IMM3J电池中造成均匀的位移损伤。光特性(LIV)结果表明,开路电压(Voc)、短路电流(Isc)和最大输出功率(Pmax)与质子注量呈对数退化规律。通过非电离能量损失（NIEL）将不同能量质子的注量转化为位移损伤剂量（DDD）,结果显示,Voc和Pmax与DDD呈对数退化规律,而Isc遵循两种不同的退化规律。光谱响应测试证明,GaInP子电池具有优异的抗辐照性能,3个子电池中InGaAs(10 eV)子电池的抗辐照性能最差。     

碳离子辐射对空间GaAs/Ge太阳电池性能影响的研究

利用2×1.7 MV串列静电加速器提供的碳(C)离子束模拟空间环境辐射,对空间GaAs/Ge太阳电池用注量为3.1×109-6.9×1012 cm-2的2 MeV C离子进行辐照.通过Ⅰ-Ⅴ特性和光谱响应测试,研究分析了GaAs/Ge太阳电池的C离子辐射效应.结果表明:随着C离子辐照注量的增加,GaAs/Ge太阳电池电性能参数Isc、Voc和Pmax衰降增大,其中Pmax衰降最大,Isc次之,Voc最小.该衰降规律和质子辐照的衰降规律相似.但使GaAs/Ge太阳电池的Pmax衰降到原值的50%,用C离子辐照所需注量要比相同射程的质子辐照小两个量级.在低注量辐照时,光谱响应衰降主要发生在长波范围;而注量大于3.1×1010 cm-2时,则发生明显的长、短波整个波段的光谱响应衰降;当注量增大到2.3×1011 cm-2以上,光谱响应基本消失.     

氦离子辐照烧结碳化硅损伤效应研究

利用中国科学院近代物理研究所320 kV高压平台提供的氦离子辐照烧结碳化硅,辐照温度从室温到1 000 ℃,辐照注量为1015~1017 cm-2。辐照完成后,进行退火处理,然后开展透射电子显微镜、拉曼光谱、纳米硬度和热导率测试。研究发现,烧结碳化硅中氦泡形核阈值注量低于单晶碳化硅。同时,氦泡形貌和尺寸与辐照温度、退火温度有关。另外,对辐照产生的晶格缺陷、元素偏析进行了研究。结果表明,辐照产生了大量的缺陷团簇,同时氦泡生长也会发射间隙子,在氦泡周围形成间隙型位错环。在晶界处,容易发生碳原子聚集。辐照导致材料先发生硬化而后发生软化,且热导率降低。     

SiC辐照损伤对耐高温氧化性能的影响

碳化硅（SiC）材料在高温氧化时会生成SiO2保护膜,但经辐照后高温氧化,材料结构和氧化速率会发生变化,影响材料性能。为研究其晶格损伤与氧化规律之间的关系,利用6H-SiC单晶片和烧结SiC多晶片,开展了在室温下经过能量为5 MeV、注量为5×1014 cm-2的Xe20+离子辐照后再进行1 300 ℃氧化1 h的实验。利用X射线衍射、拉曼光谱、傅里叶变换红外光谱、扫描电镜、透射电镜进行表征,对比了不同晶型的SiC氧化前后辐照与未辐照区域。结果显示：辐照破坏了晶格有序度,造成了晶格损伤,这些损伤在氧化过程中促进了多种SiO2基团的形成;生成的SiO2形成氧化层,由于与SiC基体热膨胀系数的差异,以及重结晶作用,导致碳化硅产生内应力,使氧化膜破裂;截面TEM图像显示,辐照引起的层错致使氧化程度加深,这是导致氧化速度加快的重要原因。     

CCD在不同注量率电子辐照下的辐射效应研究

对TCD1209线阵CCD进行能量为11MeV的电子辐照试验,采用两种不同的注量率辐照后,对器件进行常温退火试验,在辐照与退火过程中考察CCD的光响应灵敏度、暗电流、参考电平、功耗电流等特性参数的变化规律。结果表明,CCD受电子辐照后主要产生电离总剂量损伤,在不同注量率电子辐照下的辐射损伤效应类似于MOS器件的时间相关效应。     

GaAs太阳电池引入量子阱结构后抗辐射性能的变化

利用2×1.7 MV串列静电加速器提供的质子束模拟空间环境辐射,对引入量子阱GaAs太阳电池和无量子阱GaAs太阳电池进行2MeV质子注量为1×109-2×1013cm-2的辐照,通过电池Ⅰ-Ⅴ特性和光谱响应测试,研究分析了它们的辐射效应.结果表明这两种电池的Isc、Voc和Pmax的衰降幅度均随辐照注量增加而增大;而相同注量的辐照,引入量子阱GaAs太阳电池电性能衰降幅度要比无量子阱GaAs太阳电池的大.经2×1013cm-2质子辐照后,引入量子阱GaAs太阳电池光谱响应在400-1000nm整个波段有明显衰降,且长波区(900-1000 nm)的量子阱特性消失.量子阱结构的引入使GaAs太阳电池的抗辐射性能下降.     

高能重离子辐照制备SiOC复合材料的研究

用120 kev碳离子注入非晶SiO2薄膜,再用高能Xe、Pb和U离子辐照.注碳剂量范围为2.0×1017-8.6×1017 cm-2,高能离子辐照剂量1.0×1010-3.8×1012 cm-2.辐照后的样品用傅里叶变换红外光谱仪进行系统分析.实验结果显示,高能离子辐照在注碳非晶SiO2薄膜中形成了大量的Si-O-C键和Si-C键.这些Si-O-C结构具有环链、开链和笼链等多种结构形式.随电子能损、辐照剂量或者沉积能量密度的增加,SiOC结构由类笼向环/开链结构演化.对高能重离子驱动产生SiOC结构的机理进行了简单的讨论.     

Ion irradiation—induced structure damage to botanic samples using the ion transmission energy spectrum

1 INTRODUCTIONThe new aPplications of low energy heavy ion beam in irradi4ted botanical materialswere studied in recellt yeaxs. The beaminduced mutation effect on crop seeds has causedthe attention of physicist and biologists.[1l:] FOr examPle, 1ow energy ions can induceremarkable mutation to rice seeds.[3] There are many special phenomena when heavyions bombard botanic sW1e due to its special structure. Some studies showed that tllepenetration depths of some ions were far larger than t…     

Phase changes of the ZrO2—12wt%Y2O3 film with Ar^＋ irradiation

1IntroductionYttrisistabilizedzirconiawithahighresistivityandalargerelativedielectricconstant.isaveryattractiveelectricalinsulator.11]Itcanbeusedforthefabricationofsilicon-oninsulator(SOI)structuresorasthebufferlayerinhighToceramicsuperconductorsonSttoavoidthereactionbetweenStandthesuperconductorfilm.[2]Thepolymorphicbehaviourofzirconiabasedceramicscontaininglessthan20wt%Yaosstillaffectsitsthermalshock-resistancewhenitisusedoveralargetemperaturerange.Ithasbeenfoundthatthereseemsacorrelesnon…     

GaP高能重离子辐照损伤及退火的正电子湮没研究

用正电子湮没寿命技术研究２．４＊１０＾１５／ｃｍ＾２和２．２＊１０＾１６／ｃｍ＾２ ８５ＭｅＶ＾１９Ｆ离子辐照ＧａＰ的辐照损伤及其退火效应。结果表明,高低两种注量辐照在ＧａＰ中产生浓度较高的单空位。在３００－１０２３Ｋ温度范围内测量了正电子湮没寿命温度的变化。低注量辐照品在退火过程中有双空位的形成;而高注量辐照样品中观察到比双空位更复杂的缺陷形式,其完全被退火的温度比低剂量辐照的高２５０Ｋ。     

Radiation Effects on GaAs Charge Coupled Devices with High Resistivity Gate Structures

The results of a study on the effects of 1 MeV electrons and 1 MeV neutrons on the operation of high speed GaAs Charge Coupled Devices (CCDs) are presented. Radiation-induced trapping levels are characterized using a linear array CCD structure and the periodic pulse technique. 1 MeV electron irradiation introduced traps at 0.1 eV and 0.39 eV with bulk trap introduction rates of 1 cm-1 and 0.33 cm-1, respectively. The devices were irradiated to a maximum fluence of 9×1014 electrons/cm2. 1 MeV neutron irradiation introduced an electron trap level at 0.64 eV with a bulk trap introduction rate of 0.5 cm-1. Catastrophic device failure occurred at neutron fluences of 6×1013 neutrons/cm2. Device charge transfer efficiency was characterized pre- and post-irradiation over the temperature range of 80°K to 300°K.     

Low temperature resistivity study of nanostructured polypyrrole films under electronic excitations

The synthesis of nanostructured polypyrrole (Ppy) films by electrochemical process and their modifications by electronic excitations induced by swift heavy ion irradiations is reported in this paper. The electrical property of ion beam irradiated polypyrrole was investigated at low temperature by resistivity measurements. The structural and optical properties were also studied using X-ray diffraction (XRD), UV-vis spectroscopy and scanning electron microscopy (SEM). At low temperature, the polypyrrole films show the metallic behaviour after ion beam irradiation. UV-vis spectroscopy shows a red shift in the absorbance edge and thus reduction in band gap with increasing ion fluence. The structural studies show that the percentage crystallinity improves with increase in ion fluence. The SEM study corroborates the results of structural analysis and shows the formation of rod type structures along with the evolution of amorphous phase with increasing ion fluence.     

Nucleation and growth of defect clusters in CeO2 irradiated with electrons

Nucleation and growth process of defect clusters in cerium dioxide (CeO₂) with fluorite-type crystal structure has been investigated in situ under electron irradiation by using high voltage transmission electron microscopy. Planar defect clusters were formed with electron irradiation ranging from 200 to 1000 keV at temperatures below 450 K. The defect clusters were determined to be faulted-interstitial type dislocation loops lying on {1 1 1} planes. The growth rate of dislocation loops was found to increase with decreasing electron energy. An analysis of the fluence dependence of the growth process of dislocation loops suggests an increase in the vacancy mobility with decreasing electron energy. The rate of the electronic excitation is discussed in terms of the radiation-induced diffusion of oxygen-ion vacancies.     

硅三极管电子辐照的残余电压效应

研究了双极型晶体管（BJT）高能电子（1。5 MeV）辐照的总注量效应,电子辐照的总注量为5×10¹³～1.2×10¹⁶ cm^-2。实验结果表明,三极管经电子辐照后,有残余电压产生,残余电压随电子总注量的增加而增大。认为是由于辐照后产生的缺陷能级导致的去载流子效应使得BC结自建电势差变化量大于BE结,以及缺陷能级使BC结导带差变化量大于BE结这两方面原因引起的。     

Dynamic polarization of graphene by moving external charges: Comparison with 2D electron gas

We calculate the stopping and image forces on a point charge moving over a single-layer graphene grown on an SiC substrate, and compare them with forces arising when a charge moves over a two-dimensional electron gas (2DEG) in an Ag monolayer on a Si substrate. Given that both these systems constitute a one-atom thick 2DEG, major differences are found in the velocity and distance dependencies of the two forces owing to different electronic structures of the respective 2DEG. Within the massless Dirac fermion picture of graphene’s π electron bands, the inter-band single particle excitations are found to affect the stopping and image forces at high speeds in a substantial way, whereas such excitations are absent in the 2DEG of the metallic layer described by a single parabolic band.     

The energy dependence of proton-induced degradation in AlGaN/GaN high electron mobility transistors

The effects of proton irradiation at various energies are reported for AlGaN/GaN high electron mobility transistors (HEMTs). The devices exhibit little degradation when irradiated with 15-, 40-, and 105-MeV protons at fluences up to 10/sup 13/ cm/sup -2/, and the damage completely recovers after annealing at room temperature. For 1.8-MeV proton irradiation, the drain saturation current decreases 10.6% and the maximum transconductance decreases 6.1% at a fluence of 10/sup 12/ cm/sup -2/. The greater degradation measured at the lowest proton energy considered here is caused by the much larger nonionizing energy loss of the 1.8-MeV protons.