穿透型V形坑对GaN基p-i-n结构紫外探测器反向漏电的影响

研究了GaN基p-i-n(p-AlGaN/i-GaN,n-GaN)结构紫外探测器的漏电机理.实验发现,在位错密度几乎相同的情况下,基于表面有较高密度的V形坑缺陷材料制备的器件表现出较高的反向漏电.进一步的SEM测试发现,这种V形坑穿透到有源区i-GaN、甚至n-GaN层.在制备p-AlGaN电极时,许多金属会落在V形坑中,从而与i-GaN形成了肖特基接触.有些甚至直接和n-GaN形成欧姆接触.正是由于并联的肖特基接触和欧姆接触的存在导致了漏电的增加.

非晶硅太阳电池光照J-V特性的AMPS模拟

运用AMPS(Analysis of Microelectronic and Photonic Structures)模拟分析了TCO/p-a-SiC:H/i-a-Si:H/n-a-Si:H/metal结构的异质结非晶硅太阳电池中的p/i界面的价带失配以及TCO/p,n/metal界面接触势垒对电池光电特性的影响.分析总结了非晶硅基薄膜太阳电池中J-V曲线异常拐弯现象的种类和可能原因.

电化学C-V法研究磁性GaMnSb/GaSb单晶的载流子浓度纵向分布

采用电化学C-V方法和Tiron电解液研究了GaMnSb/GaSb单晶载流子浓度的纵向分布，所得结果与Hall测量结果和X射线衍射分析结果一致。研究结果表明GaMnSb单晶中的Mn原子替代了GaSb中部分Ga原子的位置，并在GaSb中形成了浅受主能级。

赝配GaAs/In_(0.2)Ga_(0.8)As量子阱导带不连续量的C-V和电容瞬态测量

半导体材料开放实验室基金,国家自然科学基金

气态源分子束外延InP和InAs基Ⅲ-V族化合物材料

简要报告气态源分子束外延实验结果。材料是GaAs(100)衬底上外延的晶格匹配的In_y(Ga_(1-x)Al_x)_(1-y)P(x=0～1,y=0.5),InGaP/InAlP多量子阱;在InP(100)衬底上外延的InP,晶格匹配的InGaAs、InAlAs以及InP/InGaAs、InP/InAsP多量子阱,InGaAs/InAlAs HEMT等,外延实验是用国产第一台化学束外延(CBE)系统做的。

瞬态C-V方法对Al_xGa_(1-x)As中DX中心的研究

于2010-11-23批量导入

Mossbauer spectroscopy study of Fe-57 in R3Fe29-xTx (R=Y, Ce, Nd, Sm, Gd, Tb and Dy; T=V and Cr)

Fe-57 Mossbauer spectra for the Fe atoms in the R3Fe29-xTx (R=Y, Ce, Nd, Sm, Gd, Tb, Dy; T=V, Cr) compounds were collected at 4.2 K. The analysis of Mossbauer spectra was based on the results of magnetization and neutron powder diffraction measurements. The average Fe magnetic moments at 4.2 K, deduced from our data, are in accord with magnetization measurements. The average hyperfine field of Tb3Fe29-xCrx (x=1.0, 1.5, 2.0, and 3.0) decreases with increasing Cr concentration, which is also in accordance with the variation of the average Fe magnetic moment in the Tb3Fe29-xCrx compounds.

Crystallographic and magnetic properties of hydride R3Fe29-xTxHy (R=Y, Ce, Nd, Sm, Gd, Tb and Dy; T=V and Cr)

The crystallographic and intrinsic magnetic properties of hydride R3Fe29-xTxHy (R=Y, Ce, Nd, Sm, Gd, Tb, and Dy; T=V and Cr) have been investigated. The lattice constants and the unit cell volume of R3Fe29-xTxHy decrease with increasing R atomic number from Nd to Dy, except for Ce, reflecting the lanthanide contraction. Regular anisotropic expansions, mainly along the a- and b-axis rather than along the c-axis, are observed for all the compounds upon hydrogenation. Hydrogenation leads to an increase in Curie temperature. First-order magnetization processes (FOMP) occur in magnetic fields of around 1.5 T and 4.0 T at 4.2 K for Nd3Fe24.5Cr4.5H5.0 and Tb(3)Fc(27.0)Cr(2.0)H(2.8), and around 1.4 T at room temperature for Gd3Fe28.0Cr1.0H4.2 Abnormal crystallographic and magnetic properties of Ce3Fe29-xTxHy suggest that the Ce ion is non-triply ionized.

Characterization of GaSb substrate wafers for MOCVD III-V antimonides

The qualities of GaSb substrates commonly used for the preparation of III-V antimonide epilayers were studied before and after growing GaInAsSb multi-layers by MOCVD using PL, FTIR and DCXD together with the electrical properties and EPD value. The correlation between the substrate qualities and epilayer properties was briefly discussed. The good property epilayers of GaInAsSb and, then, the high preformance of 2.3 um photodetectors were achieved only using the good quality GaSb wafers as the substrates.