| Record 1 of 13 |
| Author(s): Sun, LL (Sun, Lili); Yan, FW (Yan, Fawang); Zhang, HX (Zhang, Huixiao); Wang, JX (Wang, Junxi); Zeng, YP (Zeng, Yiping); Wang, GH (Wang, Guohong); Li, JM (Li, Jinmin) |
| Title: The impact of implantation dose on the characteristics of diluted-magnetic nonpolar GaN:Cu films |
| Source: MATERIALS LETTERS, 63 (29): 2574-2576 DEC 15 2009 |
| Abstract: Diluted-magnetic nonpolar GaN:Cu films have been fabricated by implanting Cu ions into p-type nonpolar a-plane (1120) GaN films with a subsequent thermal annealing process. The impact of the implantation dose on the structural. morphological and magnetic characteristics of the samples have been investigated by means of high-resolution X-ray diffraction (HRXRD). atomic force microscopy (AFM), and superconducting quantum interference device (SQUID). The XRD and AFM analyses show that the structural and morphological characteristics of samples deteriorated with the increase of implantation dose. According to the SQUID analysis. obvious room-temperature ferromagnetic properties of samples were detected. Moreover, the saturation magnetization per Cu atom decreased as the implantation dose increased. (C) 2009 Elsevier B.V. All rights reserved. |
| ISSN: 0167-577X |
| DOI: 10.1016/j.matlet.2009.09.007 |
| Record 2 of 13 |
| Author(s): Wang, ZG (Wang, Zhiguo); Wang, SJ (Wang, Shengjie); Li, JB (Li, Jingbo); Gao, F (Gao, Fei); Weber, WJ (Weber, William J.) |
| Title: Structure and Electronic Properties of Saturated and Unsaturated Gallium Nitride Nanotubes |
| Source: JOURNAL OF PHYSICAL CHEMISTRY C, 113 (44): 19281-19285 NOV 5 2009 |
| Abstract: The atomic and electronic structures of saturated and unsaturated GaN nanotubes along the [001] direction with (100) lateral facets are studied using first-principles calculations. Atomic relaxation of nanotubes shows that appreciable distortion occurs in the unsaturated nanotubes. All the nanotubes considered, including saturated and unsaturated ones, exhibit semiconducting, with a direct band gap Surface states arisen from the 3-fold-coordinated N and Ga atoms at the lateral facets exist inside the bulklike band gap. When the nanotubes are saturated with hydrogen, these dangling bond bands are removed from the band gap, but the band gap decreases with increasing the wall thickness of the nanotubes. |
| ISSN: 1932-7447 |
| DOI: 10.1021/jp907657z |
| Record 3 of 13 |
| Author(s): Zhu, NH (Zhu NingHua) |
| Title: SPECIAL TOPIC: High-Speed Optoelectronics |
| Source: CHINESE SCIENCE BULLETIN, 54 (20): 3617-3617 OCT 2009 |
| ISSN: 1001-6538 |
| DOI: 10.1007/s11434-009-0642-0 |
| Record 4 of 13 |
| Author(s): Zhu, HL (Zhu HongLiang); Liang, S (Liang Song); Zhao, LJ (Zhao LingJuan); Kong, DH (Kong DuanHua); Zhu, NH (Zhu NingHua); Wang, W (Wang Wei) |
| Title: A selective area growth double stack active layer electroabsorption modulator integrated with a distributed feedback laser |
| Source: CHINESE SCIENCE BULLETIN, 54 (20): 3627-3632 OCT 2009 |
| Abstract: A new method for fabricating electroabsorption modulator integrated with a distributed feedback laser (EML) was proposed. With the method we fabricated a selective area growth double stack active layer EML (SAG-DSAL-EML). Through comparing with other fabrication methods of EMLs, the characters and the merits of the new method presented in this paper were discussed. |
| ISSN: 1001-6538 |
| DOI: 10.1007/s11434-009-0605-5 |
| Record 5 of 13 |
| Author(s): Liu, Y (Liu Yu); Chen, SF (Chen ShuoFu); Wang, X (Wang Xin); Yuan, HQ (Yuan HaiQing); Liang, X (Liang, Xie); Zhu, NH (Zhu NingHua) |
| Title: Overall optimization of high-speed semiconductor laser modules |
| Source: CHINESE SCIENCE BULLETIN, 54 (20): 3697-3703 OCT 2009 |
| Abstract: Based on the high frequency techniques such as frequency response measurement, equivalent circuit modeling and packaging parasitics compensation, a comprehensive optimization method for packaging high-speed semiconductor laser module is presented in this paper. The experiments show that the small-signal magnitude frequency response of the TO packaged laser module is superior to that of laser diode in frequencies, and the in-band flatness and the phase-frequency linearity are also improved significantly. |
| ISSN: 1001-6538 |
| DOI: 10.1007/s11434-009-0419-5 |
| Record 6 of 13 |
| Author(s): Liu, HW (Liu, Hongwei); Kan, Q (Kan, Qiang); Wang, CX (Wang, Chunxia); Yu, F (Yu, Feng); Xu, XS (Xu, Xingsheng); Chen, HD (Chen, Hongda) |
| Title: Light extraction of GaN LEDs with 2-D photonic crystal structure |
| Source: CHINESE OPTICS LETTERS, 7 (10): 918-920 Sp. Iss. SI OCT 10 2009 |
| Abstract: Ultraviolet photo-lithography is employed to introduce two-dimensional (2D) photonic crystal (PC) structure on the top surface of GaN-based light emitting diode (LED). PC patterns are transferred to 460-nm-thick transparent indium tin oxide (ITO) electrode by inductively coupled plasma (ICP) etching. Light intensity of PC-LED can be enhanced by 38% comparing with the one without PC structure. Rigorous coupled wave analysis method is performed to calculate the light transmission spectrum of PC slab. Simulation results indicate that total internal reflect angle which modulated by PC structure has been increased by 7 degrees, which means that the light extraction efficiency is enhanced outstandingly. |
| ISSN: 1671-7694 |
| DOI: 10.3788/COL20090710.0918 |
| Record 7 of 13 |
| Author(s): Ding, K (Ding, K.); Zeng, YP (Zeng, Y. P.); Wei, XC (Wei, X. C.); Li, ZC (Li, Z. C.); Wang, JX (Wang, J. X.); Lu, HX (Lu, H. X.); Cong, PP (Cong, P. P.); Yi, XY (Yi, X. Y.); Wang, GH (Wang, G. H.); Li, JM (Li, J. M.) |
| Title: A wide-narrow well design for understanding the efficiency droop in InGaN/GaN light-emitting diodes |
| Source: APPLIED PHYSICS B-LASERS AND OPTICS, 97 (2): 465-468 OCT 2009 |
| Abstract: The electroluminescence efficiency at room temperature and low temperature (15 K) in a wide-narrow-well InGaN/GaN light-emitting diode with a narrow last well (1.5 nm) and a narrow next-to-last barrier (5 nm) is investigated to study the efficiency droop phenomenon. A reduced droop in the wide wells and a reduced droop at low temperatures reveals that inferior hole transportation ability induced Auger recombination is the root for the droop at high excitation levels. |
| ISSN: 0946-2171 |
| DOI: 10.1007/s00340-009-3657-y |
| Record 8 of 13 |
| Author(s): Li, YL (Li, Y-L.); Feng, P (Feng, P.); Wu, NJ (Wu, N-J.) |
| Book Group Author(s): IEEE |
| Title: An Embedded Ultra Low Power Nonvolatile Memory in a Standard CMOS Logic Process |
| Source: EDSSC: 2008 IEEE INTERNATIONAL CONFERENCE ON ELECTRON DEVICES AND SOLID-STATE CIRCUITS: 100-103 2008 |
| Conference Title: IEEE International Conference of Electron Devices and Solid-State Circuits |
| Conference Date: DEC 08-10, 2008 |
| Conference Location: Hong Kong, PEOPLES R CHINA |
| Abstract: This paper proposes an embedded ultra low power nonvolatile memory in a standard CMOS logic process. The memory adopts a bit cell based on the differential floating gate PMOS structure and a novel operating scheme. It can greatly improve the endurance and retention characteristic and make the area/bit smaller. A new high efficiency all-PMOS charge pump is designed to reduce the power consumption and to increase the power efficiency. It eliminates the body effect and can generate higher output voltage than conventional structures for a same stage number. A 32-bit prototype chip is fabricated in a 0.18 mu m 1P4M standard CMOS logic process and the core area is 0.06 mm(2). The measured results indicate that the typical write/erase time is 10ms. With a 700 kHz clock frequency, power consumption of the whole memory is 2.3 mu A for program and 1.2 mu A for read at a 1.6V power supply. |
| ISBN: 978-1-4244-2539-6 |
| Record 9 of 13 |
| Author(s): Lu, QY (Lu, Quan-Yong); Zhang, W (Zhang, Wei); Wang, LJ (Wang, Li-Jun); Liu, JQ (Liu, Jun-Qi); Li, L (Li, Lu); Liu, FQ (Liu, Feng-Qi); Wang, ZG (Wang, Zhan-Guo) |
| Title: Holographic fabricated photonic-crystal distributed-feedback quantum cascade laser with near-diffraction-limited beam quality |
| Source: OPTICS EXPRESS, 17 (21): 18900-18905 OCT 21 2009 |
| Abstract: We demonstrate the fabrication and characterization of photonic-crystal distributed-feedback quantum cascade laser emitting at 4.7 mu m. The tilted rectangular-lattice PCDFB structure was defined using a multi-exposure of two-beam holographic lithography. The devices exhibit the near-diffraction-limited beam emission with the full width at half maximum of the far-field divergence angles about 4.5 degrees and 2.5 degrees for stripe widths of 55 mu m and 95 mu m, respectively. Single-mode emission with a side mode suppression ratio of approximate to 20 dB is achieved in the temperature range (80-210 K). The single-facet output power is above 1 W for a 95 mu m x 2.5 mm laser bar at 85 K in pulsed operation. (C) 2009 Optical Society of America |
| ISSN: 1094-4087 |
| Record 10 of 13 |
| Author(s): Wang, J (Wang, Jun); Li, SS (Li, Shu-Shen); Lu, YW (Lue, Yan-Wu); Liu, XL (Liu, Xiang-Lin); Yang, SY (Yang, Shao-Yan); Zhu, QS (Zhu, Qin-Sheng); Wang, ZG (Wang, Zhan-Guo) |
| Title: Binding Energy and Spin-Orbit Splitting of a Hydrogenic Donor Impurity in AlGaN/GaN Triangle-Shaped Potential Quantum Well |
| Source: NANOSCALE RESEARCH LETTERS, 4 (11): 1315-1318 NOV 2009 |
| Abstract: In the framework of effective-mass envelope function theory, including the effect of Rashba spin-orbit coupling, the binding energy E-b and spin-orbit split energy Gamma of the ground state of a hydrogenic donor impurity in AlGaN/GaN triangle-shaped potential heterointerface are calculated. We find that with the electric field of the heterojunction increasing, (1) the effective width of quantum well (W) over bar decreases and (2) the binding energy increases monotonously, and in the mean time, (3) the spin-orbit split energy Gamma decreases drastically. (4) The maximum of Gamma is 1.22 meV when the electric field of heterointerface is 1 MV/cm. |
| ISSN: 1931-7573 |
| DOI: 10.1007/s11671-009-9398-3 |
| Record 11 of 13 |
| Author(s): Wen, C (Wen, C.); Wang, YM (Wang, Y. M.); Wan, W (Wan, W.); Li, FH (Li, F. H.); Liang, JW (Liang, J. W.); Zou, J (Zou, J.) |
| Title: Nature of interfacial defects and their roles in strain relaxation at highly lattice mismatched 3C-SiC/Si (001) interface |
| Source: JOURNAL OF APPLIED PHYSICS, 106 (7): Art. No. 073522 OCT 1 2009 |
| Abstract: Misfit defects in a 3C-SiC/Si (001) interface were investigated using a 200 kV high-resolution electron microscope with a point resolution of 0.194 nm. The [110] high-resolution electron microscopic images that do not directly reflect the crystal structure were transformed into the structure map through image deconvolution. Based on this analysis, four types of misfit dislocations at the 3C-SiC/Si (001) interface were determined. In turn, the strain relaxation mechanism was clarified through the generation of grow-in perfect misfit dislocations (including 90 degrees Lomer dislocations and 60 degrees shuffle dislocations) and 90 partial dislocations associated with stacking faults. (C) 2009 American Institute of Physics. [doi:10.1063/1.3234380] |
| ISSN: 0021-8979 |
| Article Number: 073522 |
| DOI: 10.1063/1.3234380 |
| Record 12 of 13 |
| Author(s): Zhou, M (Zhou Mei); Zhao, DG (Zhao De-Gang) |
| Title: A new p-n structure ultraviolet photodetector with p(-)-GaN active region |
| Source: ACTA PHYSICA SINICA, 58 (10): 7255-7260 OCT 2009 |
| Abstract: A new ultraviolet photodetector of employing p menus type GaN (p(-)-GaN) as the active layer is proposed. It is easy to obtain the p(-)-GaN layer with low carrier concentration. As a result, the depletion region can be increased and the quantum efficiency can be improved. The influence of some structure parameters on the performance of the new device is investigated. Through the simulation calculation, it is found that the quantum efficiency increases with the decrease of the barrier height between the metal electrode and the p(-)-GaN layer, and it is also found that the quantum efficiency can be improved by reducing the thickness of the p(-)-GaN layer. To fabricate the new photodetector with high performance, we should employ thin p(-)-GaN layer as the active layer and reduce the Schottky barrier height. |
| ISSN: 1000-3290 |
| Record 13 of 13 |
| Author(s): Song, GF (Song Guo-Feng); Zhang, Y (Zhang Yu); Guo, BS (Guo Bao-Shan); Wang, WM (Wang Wei-Min) |
| Title: Single mode vertical-cavity surface emitting laser with surface plasmon nanostructure |
| Source: ACTA PHYSICA SINICA, 58 (10): 7278-7281 OCT 2009 |
| Abstract: The vertical-cavity surface-emitting laser(VCSEL) has proved to be a low cost light source with attractive properties such as surface emission, circular and low divergence output beam, and simple integration in two-dimensional array. Many new applications such as in spectroscopy, optical storage, short distance fiber optic interconnects, and in longer distance communication, are continuously arising. Many of these applications require stable and single-mode high output power. Several methods that affect the transverse guiding and/or introduce mode selective loss or gain have been developed. In this study, a method for improving the single mode output power by using metal surface plasmons nanostructure is proposed. Theoretical calculation shows that the outpout power is improved about 50% compared to the result of standard VCSELs. |
| ISSN: 1000-3290 |
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