Title: Tunable dfb lasers integrated with Ti thin film heaters fabricated with a simple procedure

Addresses: [Yu, J. L.; Chen, Y. H.; Liu, Y.; Jiang, C. Y.; Ma, H.; Zhu, L. P.; Qin, X. D.] Chinese Acad Sci, Inst Semicond, Key Lab Semicond Mat Sci, Beijing 100083, Peoples R China.

Reprint Address: Yu, JL (reprint author), Chinese Acad Sci, Inst Semicond, Key Lab Semicond Mat Sci, POB 912, Beijing 100083, Peoples R China.

E-mail Addresses: jlyu@semi.ac.cn; yhchen@semi.ac.cn

ISSN: 0003-6951

Record 399 of 495

Title: In situ accurate control of 2D-3D transition parameters for growth of low-density InAs/GaAs self-assembled quantum dots

Author(s): Li, MF (Li, Mi-Feng); Yu, Y (Yu, Ying); He, JF (He, Ji-Fang); Wang, LJ (Wang, Li-Juan); Zhu, Y (Zhu, Yan); Shang, XJ (Shang, Xiang-jun); Ni, HQ (Ni, Hai-Qiao); Niu, ZC (Niu, Zhi-Chuan)

Source: NANOSCALE RESEARCH LETTERS Volume: 8 Article Number: 86 DOI: 10.1186/1556-276X-8-86 Published: FEB 18 2013

Times Cited in Web of Science: 1

Total Times Cited: 1

Abstract: A method to improve the growth repeatability of low-density InAs/GaAs self-assembled quantum dots by molecular beam epitaxy is reported. A sacrificed InAs layer was deposited firstly to determine in situ the accurate parameters of two-to three-dimensional transitions by observation of reflection high-energy electron diffraction patterns, and then the InAs layer annealed immediately before the growth of the low-density InAs quantum dots (QDs). It is confirmed by micro-photoluminescence that control repeatability of low-density QD growth is improved averagely to about 80% which is much higher than that of the QD samples without using a sacrificed InAs layer.

Addresses: [Li, Mi-Feng; Yu, Ying; He, Ji-Fang; Wang, Li-Juan; Zhu, Yan; Shang, Xiang-jun; Ni, Hai-Qiao; Niu, Zhi-Chuan] Chinese Acad Sci, Inst Semicond, State Key Lab Superlattices & Microstruct, Beijing 100083, Peoples R China.

Reprint Address: Li, MF (reprint author), Chinese Acad Sci, Inst Semicond, State Key Lab Superlattices & Microstruct, POB 912, Beijing 100083, Peoples R China.

E-mail Addresses: limifeng09@semi.ac.cn; zcniu@semi.ac.cn

ISSN: 1931-7573

Record 400 of 495

Title: Improved photovoltaic performance of silicon nanowire/organic hybrid solar cells by incorporating silver nanoparticles

Author(s): Liu, K (Liu, Kong); Qu, SC (Qu, Shengchun); Zhang, XH (Zhang, Xinhui); Tan, FR (Tan, Furui); Wang, ZG (Wang, Zhanguo)

Source: NANOSCALE RESEARCH LETTERS Volume: 8 Article Number: 88 DOI: 10.1186/1556-276X-8-88 Published: FEB 18 2013

Times Cited in Web of Science: 0

Total Times Cited: 0

Abstract: Silicon nanowire (SiNW) arrays show an excellent light-trapping characteristic and high mobility for carriers. Surface plasmon resonance of silver nanoparticles (AgNPs) can be used to increase light scattering and absorption in solar cells. We fabricated a new kind of SiNW/organic hybrid solar cell by introducing AgNPs. Reflection spectra confirm the improved light scattering of AgNP-decorated SiNW arrays. A double-junction tandem structure was designed to manufacture our hybrid cells. Both short-circuit current and external quantum efficiency measurements show an enhancement in optical absorption of organic layer, especially at lower wavelengths.

Addresses: [Liu, Kong; Qu, Shengchun; Tan, Furui; Wang, Zhanguo] Chinese Acad Sci, Inst Semicond, Key Lab Semicond Mat Sci, Beijing 100083, Peoples R China.

[Zhang, Xinhui] Chinese Acad Sci, Inst Semicond, State Key Lab Superlattices & Microstruct, Beijing 100083, Peoples R China.

Reprint Address: Qu, SC (reprint author), Chinese Acad Sci, Inst Semicond, Key Lab Semicond Mat Sci, Beijing 100083, Peoples R China.

E-mail Addresses: qsc@semi.ac.cn

ISSN: 1931-7573
--------------------------------------------------------------------------------

Record 401 of 495

Title: High-speed microwave photonic switch for millimeter-wave ultra-wideband signal generation

Author(s): Wang, LX (Wang, Li Xian); Li, W (Li, Wei); Zheng, JY (Zheng, Jian Yu); Wang, H (Wang, Hui); Liu, JG (Liu, Jian Guo); Zhu, NH (Zhu, Ning Hua)

Source: OPTICS LETTERS Volume: 38 Issue: 4 Pages: 579-581 Published: FEB 15 2013

Times Cited in Web of Science: 3

Total Times Cited: 3

Abstract: We propose a scheme for generating millimeter-wave (MMW) ultra-wideband (UWB) signal that is free from low-frequency components and a residual local oscillator. The system consists of two cascaded polarization modulators and is equivalent to a high-speed microwave photonic switch, which truncates a sinusoidal MMW into short pulses. The polarity switchability of the generated MMW-UWB pulse is also demonstrated. (C) 2013 Optical Society of America

Addresses: [Wang, Li Xian; Li, Wei; Zheng, Jian Yu; Wang, Hui; Liu, Jian Guo; Zhu, Ning Hua] Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China.

Reprint Address: Wang, LX (reprint author), Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, POB 912, Beijing 100083, Peoples R China.

E-mail Addresses: lxwang@semi.ac.cn

ISSN: 0146-9592

Record 402 of 495

Title: Widely-Tunable and Background-Free Ultra-Wideband Signals Generation Utilizing Polarization Modulation-Based Optical Switch

Author(s): Du, YX (Du, Yuanxin); Zheng, JY (Zheng, Jianyu); Wang, LX (Wang, Lixian); Wang, H (Wang, Hui); Zhu, NH (Zhu, Ninghua); Liu, JG (Liu, Jianguo)

Source: IEEE PHOTONICS TECHNOLOGY LETTERS Volume: 25 Issue: 4 Pages: 335-337 DOI: 10.1109/LPT.2013.2238526 Published: FEB 15 2013

Times Cited in Web of Science: 3

Total Times Cited: 3

Abstract: A simple widely-tunable and background-free ultra-wideband (UWB) pulse shaper by utilizing the polarization modulation-based optical switch is proposed and demonstrated. By virtue of the excellent switch isolation and the complementarity between two inverted baseband signals output from the optical switch, the local oscillator leakage signal and the low frequency components of the obtained UWB signals are suppressed very well. The UWB pulse with center frequency up to 28 GHz is generated.

Addresses: [Du, Yuanxin; Zheng, Jianyu; Wang, Lixian; Wang, Hui; Zhu, Ninghua; Liu, Jianguo] Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 10083, Peoples R China.

Reprint Address: Du, YX (reprint author), Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 10083, Peoples R China.

E-mail Addresses: yxdu@semi.ac.cn; jyzheng@semi.ac.cn; lxwang@semi.ac.cn; whui@semi.ac.cn; nhzhu@semi.ac.cn; jgliu@semi.ac.cn

ISSN: 1041-1135

Record 403 of 495

Title: Synthesis of Novel Acceptor Molecules of Mono- and Multiadduct Fullerene Derivatives for Improving Photovoltaic Performance

Author(s): Liu, C (Liu, Chao); Xu, L (Xu, Liang); Chi, D (Chi, Dan); Li, YJ (Li, Yongjun); Liu, HB (Liu, Huibiao); Wang, JZ (Wang, Jizheng)

Source: ACS APPLIED MATERIALS & INTERFACES Volume: 5 Issue: 3 Pages: 1061-1069 DOI: 10.1021/am3028475 Published: FEB 13 2013

Times Cited in Web of Science: 0

Total Times Cited: 0

Abstract: We have successfully synthesized and separated a series of tert-butyl 4-C-61-benzoate (t-BCB) organofullerenes, including monoadduct, diadduct, and triadduct compounds, and investigated their photophysics, electrochemistry, thermal properties, and high-performance liquid chromatography analysis. The photovoltaic devices were fabricated based on monoadduct, diadduct, and triadduct products, and the devices based on them exhibited power conversion efficiencies of 2.43%, 0.48%, and 1.68%, respectively. This was the first time to study the dependent relationship on the device performance and the different isomer numbers.

Addresses: [Liu, Chao; Xu, Liang; Chi, Dan; Li, Yongjun; Liu, Huibiao; Wang, Jizheng] Chinese Acad Sci, Inst Chem, CAS Key Lab Organ Solids, BNLMS, Beijing 100190, Peoples R China.

[Liu, Chao; Xu, Liang] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.

[Chi, Dan] Chinese Acad Sci, Inst Semicond, Key Lab Semicond Mat Sci, Beijing 100083, Peoples R China.

Reprint Address: Liu, HB (reprint author), Chinese Acad Sci, Inst Chem, CAS Key Lab Organ Solids, BNLMS, Beijing 100190, Peoples R China.

E-mail Addresses: liuhb@iccas.ac.cn

ISSN: 1944-8244

Record 404 of 495

Title: Nitride-based micron-scale hexagonal pyramids array vertical light emitting diodes by N-polar wet etching

Author(s): Ma, J (Ma, Jun); Wang, LC (Wang, Liancheng); Liu, ZQ (Liu, Zhiqiang); Yuan, GD (Yuan, Guodong); Ji, XL (Ji, Xiaoli); Ma, P (Ma, Ping); Wang, JX (Wang, Junxi); Yi, XY (Yi, Xiaoyan); Wang, GH (Wang, Guohong); Li, JM (Li, Jinmin)

Source: OPTICS EXPRESS Volume: 21 Issue: 3 Pages: 3547-3556 Published: FEB 11 2013

Times Cited in Web of Science: 1

Total Times Cited: 1

Abstract: In this work, we reported the fabrication of nitride-based hexagonal pyramids array (HPA) vertical-injection light emitting diodes (V-LEDs) by N-polar wet etching. The performance of HPA V-LEDs devices was significantly improved with 30% higher internal quantum efficiency compared with conventional roughened broad area V-LEDs. The simulated extraction efficiency by finite difference time domain method was 20% higher than typical roughened V-LEDs. The reversed leakage current of HPA V-LEDs was reduced due to better crystal quality, which was confirmed by conductive atomic force microscopy measurement. Furthermore, the efficiency droop for HPA V-LEDs were substantially alleviated. (C) 2013 Optical Society of America

Addresses: [Ma, Jun; Wang, Liancheng; Liu, Zhiqiang; Yuan, Guodong; Ji, Xiaoli; Ma, Ping; Wang, Junxi; Yi, Xiaoyan; Wang, Guohong; Li, Jinmin] Chinese Acad Sci, Inst Semicond, Res & Dev Ctr Semicond Lighting, Beijing 100083, Peoples R China.

Reprint Address: Ma, J (reprint author), Chinese Acad Sci, Inst Semicond, Res & Dev Ctr Semicond Lighting, Beijing 100083, Peoples R China.

E-mail Addresses: spring@semi.ac.cn

ISSN: 1094-4087

Record 405 of 495

Title: Polarization of the edge emission from Ag/InGaAsP Schottky plasmonic diode

Author(s): Wang, C (Wang, C.); Qu, HJ (Qu, H. J.); Chen, WX (Chen, W. X.); Ran, GZ (Ran, G. Z.); Yu, HY (Yu, H. Y.); Niu, B (Niu, B.); Pan, JQ (Pan, J. Q.); Wang, W (Wang, W.)

Source: APPLIED PHYSICS LETTERS Volume: 102 Issue: 6 Article Number: 061112 DOI: 10.1063/1.4792508 Published: FEB 11 2013

Times Cited in Web of Science: 0

Total Times Cited: 0

Abstract: Electrical plasmonic sources with compact sizes are a fundamental component in plasmonics. Here, we report a simple plasmonic diode having an Ag/InGaAsP quantum well Schottky structure. The polarization ratio (TM:TE) of the edge-emission photoluminescence for the quantum wells is about 2:1 and increases to about 3:1 after covered by Ag. As contrast, the electroluminescence polarization ratio exceeds 10:1 at a low current, indicating a high plasmon generation efficiency but drops gradually as current increasing; simultaneously, the peak wavelength red shifts evidently, which are attributed to the recombination zone shift and quantum confinement Stark effect. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4792508]

Addresses: [Wang, C.; Qu, H. J.; Chen, W. X.; Ran, G. Z.] Peking Univ, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China.

[Wang, C.; Qu, H. J.; Chen, W. X.; Ran, G. Z.] Peking Univ, Sch Phys, Beijing 100871, Peoples R China.

[Yu, H. Y.; Niu, B.; Pan, J. Q.; Wang, W.] Chinese Acad Sci, Inst Semicond, Key Lab Semicond & Mat Sci, Beijing 100083, Peoples R China.

Reprint Address: Wang, C (reprint author), Peking Univ, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China.

E-mail Addresses: rangz@pku.edu.cn; jqpan@semi.ac.cn

ISSN: 0003-6951

Record 406 of 495

Title: Robust 3-component optical fiber accelerometer for seismic monitoring

Author(s): Jiang, DS (Jiang, Dongshan); Zhaug, FX (Zhaug, Faxiang); Zhang, WT (Zhang, Wentao); Li, F (Li, Feng); Li, F (Li, Fang)

Source: CHINESE OPTICS LETTERS Volume: 11 Issue: 2 Article Number: 020602 DOI: 10.3788/COL201311.020602 Published: FEB 10 2013

Times Cited in Web of Science: 0

Total Times Cited: 0

Abstract: A robust cantilever-based push pull 3-component (3-C) optical fiber accelerometer is proposed and experimentally demonstrated. Sensitivity and resonance frequency can be enhanced simultaneously by increasing the number of turns of an optical fiber without increasing the accelerometer size at the mass of a certain value. The calibration results show that axis sensitivity is 45 dB (re: 0 dB = 1 rad/g), with a fluctuation less than 0.9 dB in a frequency bandwidth of 10-450 Hz. The cross sensitivity is approximately 15 dB, with a fluctuation less than 1.2 dB in a frequency bandwidth of 10-450 Hz. The crosstalk reaches up to 30 dB. Fluctuation of the responses of the acceleration sensitivity of different components is less than 0.7 dB over a frequency bandwidth of 10 -450 Hz, which proves the good consistency of the 3-C optical fiber accelerometer. By usingan all-metal structure is expected to improve the reliability of the designed accelerometer for long-term use in harsh environments. These desirable features show that the proposed 3-C optical fiber accelerometer is satisfactory for seismic wave monitoringin oil and gas exploration.

Addresses: [Jiang, Dongshan; Zhaug, Faxiang; Zhang, Wentao; Li, Feng; Li, Fang] Chinese Acad Sci, Inst Semicond, Optoelect Syst Lab, Beijing 100083, Peoples R China.

Reprint Address: Zhang, WT (reprint author), Chinese Acad Sci, Inst Semicond, Optoelect Syst Lab, Beijing 100083, Peoples R China.

E-mail Addresses: zhangwt@semi.ac.cn

ISSN: 1671-7694

Record 407 of 495

Title: Ultra-compact and fabrication-tolerant polarization rotator based on a bend asymmetric-slab waveguide

Author(s): Cao, TT (Cao, Tongtong); Chen, SW (Chen, Shaowu); Fei, YH (Fei, Yonghao); Zhang, LB (Zhang, Libin); Xu, QY (Xu, Qing-Yang)

Source: APPLIED OPTICS Volume: 52 Issue: 5 Pages: 990-996 Published: FEB 10 2013

Times Cited in Web of Science: 1

Total Times Cited: 1

Abstract: We propose and analyze a polarization rotator based on a bend asymmetric-slab waveguide on the silicon-on-insulator platform. The device can be fabricated using standard complementary metal-oxide-semiconductor process involving only two dry etching steps. Compared with the formerly reported polarization rotators based on two-step etching, our introduced device demonstrates a significant improvement for fabrication tolerance. Furthermore, an ultra compact structure of similar to 5 mu m conversion length, an insertion loss of only 0.5 dB, and an extinction ratio of >40 dB for both TE to TM polarization conversion and TM to TE polarization conversion are exhibited. Operation wavelength and the influence of environmental temperature on our device are also discussed. (C) 2013 Optical Society of America

Addresses: [Cao, Tongtong; Chen, Shaowu; Fei, Yonghao; Zhang, Libin; Xu, Qing-Yang] Chinese Acad Sci, Inst Semicond, State Key Lab Optoelect, Beijing 100083, Peoples R China.

Reprint Address: Chen, SW (reprint author), Chinese Acad Sci, Inst Semicond, State Key Lab Optoelect, Beijing 100083, Peoples R China.

E-mail Addresses: swchen@semi.ac.cn

ISSN: 1559-128X

Record 408 of 495

Title: Temperature dependence of anisotropic mode splitting induced by birefringence in an InGaAs/GaAs/AlGaAs vertical-cavity surface-emitting laser studied by reflectance difference spectroscopy

Author(s): Yu, JL (Yu, Jinling); Chen, YH (Chen, Yonghai); Cheng, SY (Cheng, Shuying); Lai, YF (Lai, Yunfeng)

Source: APPLIED OPTICS Volume: 52 Issue: 5 Pages: 1035-1040 Published: FEB 10 2013

Times Cited in Web of Science: 0

Total Times Cited: 0

Abstract: The temperature dependence of the mode splitting induced by birefringence in an InGaAs/GaAs/AlGaAs vertical-cavity surface-emitting laser has been studied by reflectance difference spectroscopy at different temperatures ranging from 80 to 330 K. The anisotropic broadening width and the anisotropic integrated area of the cavity mode under different temperatures are also determined. The relation between the mode splitting and the birefringence is obtained by theoretical calculation using a Jones matrix approach. The temperature dependence of the energy position of the cavity mode and the quantum well transition are also determined by nearly normal reflectance and photoluminescence, respectively. (C) 2013 Optical Society of America

Addresses: [Yu, Jinling; Cheng, Shuying; Lai, Yunfeng] Fuzhou Univ, Coll Phys & Informat Engn, Fuzhou 350108, Fujian Province, Peoples R China.

[Yu, Jinling; Cheng, Shuying; Lai, Yunfeng] Fuzhou Univ, Inst Micro Nano Devices & Solar Cells, Fuzhou 350108, Fujian Province, Peoples R China.

[Chen, Yonghai] Chinese Acad Sci, Inst Semicond, Key Lab Semicond Mat Sci, Beijing 100083, Peoples R China.

Reprint Address: Yu, JL (reprint author), Fuzhou Univ, Coll Phys & Informat Engn, Fuzhou 350108, Fujian Province, Peoples R China.

E-mail Addresses: jlyu@semi.ac.cn; yhchen@semi.ac.cn

ISSN: 1559-128X

Record 409 of 495

Title: Electrical switching of quantum tunneling through p-n junction in a quantum spin Hall bar

Author(s): Cheng, F (Cheng, Fang); Lin, LZ (Lin, L. Z.); Zhang, LB (Zhang, L. B.); Zhou, GH (Zhou, Guanghui)

Source: JOURNAL OF APPLIED PHYSICS Volume: 113 Issue: 5 Article Number: 053708 DOI: 10.1063/1.4790325 Published: FEB 7 2013

Times Cited in Web of Science: 0

Total Times Cited: 0

Abstract: We demonstrate theoretically electrical switching of the edge state transport via a transverse electric field in a quantum spin Hall bar. By tuning the electric fields, the Fermi energy and the gate voltage, the edge channels in the both topological insulator (TI)/band insulator (BI) and TI/TI p-n junctions can be transited from opaque to transparent. This electrical switching behavior offers us an efficient way to control the topological edge state transport which is robust against the local perturbation. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4790325]

Addresses: [Cheng, Fang] Changsha Univ Sci & Technol, Dept Phys & Elect Sci, Changsha 410004, Hunan, Peoples R China.

[Cheng, Fang; Lin, L. Z.] Chinese Acad Sci, Inst Semicond, SKLSM, Beijing 100083, Peoples R China.

[Zhang, L. B.; Zhou, Guanghui] Hunan Normal Univ, Dept Phys, Changsha 410081, Hunan, Peoples R China.

[Zhang, L. B.; Zhou, Guanghui] Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Manipulat, Changsha 410081, Hunan, Peoples R China.

Reprint Address: Cheng, F (reprint author), Changsha Univ Sci & Technol, Dept Phys & Elect Sci, Changsha 410004, Hunan, Peoples R China.

ISSN: 0021-8979

Record 410 of 495

Title: Electrical transport properties of boron-doped single-walled carbon nanotubes

Author(s): Li, YF (Li, Y. F.); Wang, Y (Wang, Y.); Chen, SM (Chen, S. M.); Wang, HF (Wang, H. F.); Kaneko, T (Kaneko, T.); Hatakeyama, R (Hatakeyama, R.)

Source: JOURNAL OF APPLIED PHYSICS Volume: 113 Issue: 5 Article Number: 054313 DOI: 10.1063/1.4790505 Published: FEB 7 2013

Times Cited in Web of Science: 0

Total Times Cited: 0

Abstract: The transport properties of B-doped single-walled carbon nanotubes (SWNTs) are studied from both experimental and theoretical standpoints. Experimentally, it is found that the semiconducting behavior of SWNTs is drastically changed after B-doping, and the unusual abrupt current drops are observed at low temperatures, which may imply the possibility of superconducting transition in B-doped SWNTs. Using the density-functional tight-binding calculation, it is observed that B-doping induces the presence of density of state peaks near the Fermi level which shifts toward the valence band region, showing a clear charge-transfer characteristic, which agrees well with the experimental observations. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4790505]

Addresses: [Li, Y. F.] China Univ Petr, State Key Lab Heavy Oil Proc, Beijing 102249, Changping, Peoples R China.

[Li, Y. F.; Kaneko, T.; Hatakeyama, R.] Tohoku Univ, Dept Elect Engn, Sendai, Miyagi 9808579, Japan.

[Wang, Y.] Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Rare Earth Resource Utilizat, Changchun 130022, Peoples R China.

[Chen, S. M.] Chinese Acad Sci, Inst Proc Engn, Beijing 100190, Peoples R China.

[Wang, H. F.] Chinese Acad Sci, Inst Semicond, Beijing 100083, Peoples R China.

Reprint Address: Li, YF (reprint author), China Univ Petr, State Key Lab Heavy Oil Proc, Beijing 102249, Changping, Peoples R China.

E-mail Addresses: liyongfeng2004@yahoo.com.cn

ISSN: 0021-8979

Record 411 of 495

Title: Oxygen pressure manipulations on the metal-insulator transition characteristics of highly (0 1 1)-oriented vanadium dioxide films grown by magnetron sputtering

Author(s): Yu, Q (Yu, Qian); Li, WW (Li, Wenwu); Liang, JR (Liang, Jiran); Duan, ZH (Duan, Zhihua); Hu, ZG (Hu, Zhigao); Liu, J (Liu, Jian); Chen, HD (Chen, Hongda); Chu, JH (Chu, Junhao)

Source: JOURNAL OF PHYSICS D-APPLIED PHYSICS Volume: 46 Issue: 5 Article Number: 055310 DOI: 10.1088/0022-3727/46/5/055310 Published: FEB 6 2013

Times Cited in Web of Science: 1

Total Times Cited: 1

Abstract: The metal-insulator transition behaviour of vanadium dioxide (VO2) films grown at different oxygen pressures is investigated. With the aid of temperature-dependent electrical and infrared transmittance experiments, it is found that the transition temperature in the heating process goes up with increasing argon-oxygen ratio, whereas the one in the cooling process shows an inverse variation trend. It is found that the hysteresis width of the phase transition is narrowed at a lower argon-oxygen ratio because the defects introduced by excess oxygen lower the energy requirement of transformation. Furthermore, the defects reduce the forbidden gap of the VO2 system due to the generation of a V5+ ion. The present results are valuable for the achievement of VO2-based optoelectronic devices.

Addresses: [Yu, Qian; Li, Wenwu; Duan, Zhihua; Hu, Zhigao; Chu, Junhao] E China Normal Univ, Key Lab Polar Mat & Devices, Minist Educ, Dept Elect Engn, Shanghai 200241, Peoples R China.

[Liang, Jiran; Chen, Hongda] Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China.

[Liu, Jian] Chinese Acad Sci, Inst Semicond, State Key Lab Superlattices & Microstruct, Beijing 100083, Peoples R China.