气相输运法大尺寸ZnO单晶生长的传输过程控制

研究了化学气相传输法（CVT）生长ZnO单晶的传输过程、动力学和生长机理，分析了CVT法的传输机理、效率以及温场对传输速率和晶体生长的影响，利用气相-固相单晶成核和生长动力学理论研究了制约单晶生长速度和晶体质量的因素．我们得到的不同条件下ZnO单晶CVT生长的实验结果和现象与理论分析一致，获得了ZnO单晶生长的理想条件和高质量的大尺寸ZnO单晶材料。

Ferromagnetic MnSb Films Consisting of Nanorods and Nanoleaves

Ferromagnetic MnSb films were synthesized on Si wafers by physical vapor deposition. X-ray diffraction revealed that the films primarily consisted of MnSb alloy. Nanorods and nanoleaves were observed in the MnSb films by field-emission scanning electron microscopy. These nanorods had an average diameter of 20nm and a length of up to hundreds of nanometers. The nanoleaves had a width and thickness of about 100 and 20nm, respectively. Magnetic hysteresis loops were measured by an alternative gradient magnetometer, and the loops showed strong geometrical anisotropy.

PLD方法制备ZnO薄膜的特征温度研究

用PLD方法在Si(111)衬底上制备了ZnO薄膜.在薄膜的沉积过程中,用安装在激光脉冲沉积设备上的反射高能电子衍射仪(RHEED)对薄膜的生长进行了原位监测.结合薄膜的X射线衍射(XRD)分析和荧光光谱(PL)分析,发现达到或者超过650C时生长的薄膜,结构和光学特性得到了显著的改善.

ZnO单晶的缺陷及其对材料性质的影响

利用X射线衍射技术、荧光光谱、霍尔效应和光学显微等方法分别研究了ZnO单晶的品格完整性、深能级缺陷、电学性质、位错和生长极性．通过比较ZnO单晶材料在退火前后的测试结果，分析了材料的缺陷属性和缺陷对材料性质、晶体完整性的影响．

化学气相传输法生长ZnO单晶及性质研究

利用化学气相传输法生长了ZnO单晶。在无籽晶自发成核的条件下，使用碳辅助增强质量传输方法，得到了晶粒尺寸达4mm×10mm的ZnO晶体。利用长有GaN层的蓝宝石晶片作为衬底，得到了直径为30mm、厚2mm左右的ZnO单晶体。比较了不同温度条件下晶体生长的结果并进行热力学过程和现象了分析。用光荧光谱和X射线双晶衍射研究了ZnO晶体的性质。

Low -temperature preparation of ZnO films on Si substrates by MOCVD

ZnO films were deposited on Si（100） substrates at 300℃ by metal - organic chemical vapor deposition（MOCVD）. The effect of different ratios of DEZn to N2O on crystal quality was analyzed. It is found that the optimum ratio of DEZn to N2O is 2.1. And in this optimum growth condition, X - ray diffraction （XRD） and scanning probe morphology （SPM） images indicate that the films grow along the c - axis orientation. ZnO film exhibits a strong UV optical absorption near 388 nm. And the optical absorbance is close to zero,that indicates nearly 100% optical transparence. Photoluminescence （PL） spectrum shows only strong near - band - edge emissions with little or no deep - level emission related to defects. The full - width at half - maximum （FWHM） of the ultraviolet emission peak is 80meV. The results indicate that better crystal quality can be obtained.

化学气相传输法生长ZnO单晶

利用化学气相传输法生长了ZnO单晶．通过控制源区和生长端的温度梯度，使用碳辅助增强质量传尊挚应，在无籽晶自发成核的条件下，得到了晶粒尺寸达5mm×8mm的ZnO晶体．利用长有GaN层的蓝宝石号片待为籽晶，得到了直径32mm、厚4mm左右的ZnO单晶体．用光致发光谱和X射线双晶衍射研究了ZnO晶体的性质并对生长的热力学过程和现象进行了分析．

脉冲激光沉积方法制备ZnO薄膜生长参量对发光特性的影响

用脉冲激光沉积（PLD）方法在Si（111）衬底上制备了ZnO薄膜。以325nmHe-Cd激光器为光源对薄膜进行了荧光光谱分析，用X射线衍射仪（XRD）和原子力显微镜（AFM）分别对薄膜的结构和形貌进行了分析。脉冲激光沉积方法的主要生长参量为氧压、激光重复频率、生长温度和激光能量。通过控制这些参量变量，研究了这些参量对ZnO薄膜发光特性的影响，得到了用于紫外发光的ZnO薄膜生长的优化条件

慢正电子对ZnO中本征缺陷的研究

利用慢正电子研究了不同氧含量时射频磁控反应溅射制备的ZnO样品,观察到ZnO中本征缺陷（Vo,VZn）随混合气体中O2比例（PO2）的变化关系.结果表明

Effects of Thickness on Properties of ZnO Films Grown on Si by MOCVD

High quality ZnO films are successfully grown on Si（100） substrates by metal-organic chemical vapor deposition at 300℃. The effects of the thickness of the ZnO films on crystal structure, surface morphology,and optical properties are investigated using X-ray diffraction, scanning probe microscopy,and photoluminescence spectra, respectively. It is shown that the ZnO films grown on Si substrates have a highly-preferential C-axis orientation,but it is difficult to obtain the better structural and optical properties of the ZnO films with the increasing of thickness. It is maybe due to that the grain size and the growth model are changed in the growth process.

氧离子束辅助激光淀积生长ZnO/Si的研究

利用X射线衍射(XRD),X射线摇摆曲线(XRC)和X射线光电子能谱(XPS)分析方法对氧离子束辅助激光淀积生长的ZnO/Si异质结薄膜进行了分析.结果表明:用该法可生长出高度c轴单一取向ZnO薄膜,XRC的半高宽度(FWHM)仅为2.918°.表明此生长方法经优化,可生长出单晶质量很好的ZnO/Si薄膜.

溶胶-凝胶法制备ZnO纳米薄膜的工艺和应用

ZnO是一种重要的功能材料和新型的n一Ⅵ族宽禁带半导体材料。采用溶胶一凝胶(sol-gel)工艺在si(100)、si(111)和c面蓝宝石衬底上成功制备出高质量的ZnO纳米薄膜，并用XRD、SEM、AFM等方法研究了薄膜的特性。首次以制备的ZnO纳米薄膜为缓冲层，在n型si(1()o)衬底上采用低压化学气相沉积(LPCVD)工艺外延生长了SiC薄膜，得到了低载流子浓度、高电子迁移率和高空穴迁移率的两种SiC薄膜样品，分析了该薄膜的性能。

Narrow-beam divergence 1.55μm laser diodes with integrated self-aligned spotsize conVerter

This paper describes the high performance of narrow-beam divergence spot size converter (SSC) integrated separately confined heterostructure (SCH) LD. The upper optical confinement layer (OCL) and the butt-coupled tapered thickness waveguide were regrown simultaneously, which not only offered the separated optimization of the active region and the integrated spotsize converter, but also reduced the difficulty of the butt-joint selective regrowth. The threshold current was as low as 5.4 mA, the output power at 55 mA was 10.1 mW, the vertical and horizontal far field divergence angles were as low as 9°and 15°, and the 1-dB misalignment tolerances were 3.6 and 3.4μm, respectively.

Self-aligned Coupled Waveguide Distributed Bragg Reflector Lasers

A novel self-aligned coupled waveguide (SACW) multi-quantum-well (MQW) distributed Bragg reflector (DBR) laser is proposed and demonstrated for the first time. By selectively removing the MQW layer and leaving the low SCH/SACW layer the Bragg grating is partially formed on this layer. By optimizing the thickness of the low SCH/SACW layer, a ～80% coupling efficiency between the MQW gain region and the passive region are obtained. The typical threshold current of the SACW DBR laser is 39 mA, the slope efficiency can reach to 0.2 mW/mA and the output power is more than 20 mW with a more than 30dB side mode suppression ratio.

1.5μm Self-Aligned Spotsize Converter Integrated DFB Fabricated by Selective Area Grown MOVPE

High performance 1.57μm spotsize converter monolithically integrated DFB is fabricated by the technique of self-aligned selective area growth. The upper optical confinement layer and the butt-coupled tapered thickness waveguide are regrown simultaneously, which not only offeres the separated optimization of the active region and the integrated spotsize converter, but also reduces the difficulty of the butt-joint selective regrowth. The threshold current is as low as 4.4mA. The output power at 49mA is 10.1mW. The side mode suppression ratio (SMSR) is 33.2dB. The vertical and horizontal far field divergence angles are as small as 9° and 15° respectively, the 1dB misalignment tolerance are 3.6μm and 3.4μm.