Hydrogen passivated nanocrystalline Si/SiO 2 (nc-Si:H/SiO 2 ) pillar arrays were fabricated by using nanosphere lithography combination with hydrogen plasma annealing (HPA). Enhanced blue-orange-red photoluminescence (PL) could be observed by the naked eye in the bright room from the samples. By controlling the size of nc-Si:H from 3.8 to 1.8 nm, the PL peak blueshifts from 757 to 435 nm. It is found that the nanopillar structure can drastically enhance the light-absorbing properties of the samples and hydrogenation of nc-Si embedded in pillars is benefit to the increase of photoluminescence (PL) intensity. Combined with the analysis of atomic force microscope (AFM), transmission electron microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy and absorption spectra, the blue photoluminescence (PL) peak are ascribed to the quantum size effect of the nc-Si passivated by hydrogen, and the orange and red ones to both the localized surface states and quantum confinement effects of nc-Si:H. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Ma Z. Y.;Liu G. Y.;Yan M. Y.;Xia G. Y.;Jiang X. F.;Ling T.;Sun H. C.;Wang D. Q.;Dong H. P.;Xu L.;Li W.;Chen K. J.;Xu J.;Feng D.

Physica Status Solidi C Current Topics in Solid State Physics

2010

Intensive electroluminescence could be observed from nc-Si/SiO2 pillars. The electroluminescence intensity is increased by 30 times of magnitude compared to that of nc-Si/SiO2 multilayers. The enhancement of EL can be attributed to the improved extraction efficiency of emission light and the high carrier-injection efficiency. ©2010 IEEE.

Ma Z. Y.;Liu G. Y.;Xia G. Y.;Yan M. Y.;Jiang X. F.;Ling T.;Xu L.;Dong H. P.;Huang X. F.;Chen K. J.;Li W.;Feng D.

IEEE International Conference on Group IV Photonics Gfp

2010

Branchy alumina nanotubes (bANTs) have been shown to exist in aluminum oxide. Electron-beam evaporated 400 nm Al film on Si substrate is stepwise anodized in dilute sulfuric acid under the constant dc voltage 40 V at 10.0°C. This electrochemical-anodizing route resulted in the formation of individual bANTs. Transmission electron microscopy showed that the length of the bANTs was around 450 nm, and the inner diameter was around 10-20 nm. We deduced that the bANTs, the completely detached multibranchy cells of anodic porous alumina (APA) film, should be evolved from the stagnant cells of the APA mother film. The bANTs may be used as templates in fabrication of individual branchy nanoscale cables, jacks, and heterojunctions. The proposed formation mechanisms of the bANTs and the stagnant cells should give some insights into the long-standing problem of APA film, i.e., the self-ordering mechanism of the cells arrangement in porous anodization of aluminum. © 2002 American Institute of Physics.

Zou Jianping;Pu Lin;Bao Ximao;Feng Duan

Applied Physics Letters

2002

Strong and stable blue photoluminescence (PL) at room temperature has been observed from amorphous oxidized silicon nitride (a-SiN x:O) films with Ag nanoparticles inserted between a-SiN x:O films and Si substrates. The resonant excitation of localized surface plasmons (LSPs) with the emission of a-SiN x:O films has resulted in an increase in the internal quantum efficiency, from 3.9% to 8.4%. We have found that the PL efficiency ratio induced by resonant coupling is close to the enhancement of the spontaneous emission rate of a-SiN x:O, which demonstrates that a-SiN x:O films with LSP-enhanced blue emission is promising for silicon-based light-emitting applications. © 2012 American Institute of Physics.

Ma Zhongyuan;Yan Minyi;Jiang Xiaofan;Yang Huafeng;Xia Guoyin;Ni Xiaodong;Ling Tao;Li Wei;Xu Ling;Chen Kunji;Huang Xinfan;Feng Duan

Applied Physics Letters

2012

Unipolar resistive switching memory behavior is directly observed in nanocrystalline Si (nc-Si) film under atmosphere. It is found that the switching is independent of the electrode materials. No resistive switching behavior can be found in reference device without nc-Si. The nc-Si align in a pathway is observed in the HRTEM of the device after voltage was applied. Meanwhile, the same switching behavior as measured under atmosphere is also observed in vacuum. Based on the analysis of the nc-Si film structure and I-V characteristic, we further discuss the mechanism of the switching behavior. © 2012 Elsevier B.V. All rights reserved.

Xia Guoyin;Ma Zhongyuan;Jiang Xiaofan;Yang Huafeng;Xu Jun;Xu Ling;Li Wei;Chen Kunji;Feng Duan

Journal of Non Crystalline Solids

2012

Nanocrystalline (nc)-Si/SiO2multistacked floating gate have been prepared by electron beam evaporation of SiOxand SiO2followed by thermal annealing. HRXTEM reveals that the density of multiply stacked nc-Si quantum dots reaches 9.1×10¹¹cm^-2with size of 2-3 nm. The periodicity effect of nc-Si/SiO2multilayers on the charge storage characteristics of nc-Si floating gate is investigated carefully by using capacitance-voltage (C-V ) and conductance-voltage (G-V ) measurements at room temperature. It is found the charge storage ability enhances obviously with the periodicity of the multiply stacked nc-Si layer increasing from 2 to 9. The up limit of the thickness for multistacked nc-Si/SiO2layer is less than 100 nm, which is close to the mean free path of electron in multistacked nc-Si. Charge diffusion among the multistacked nc-Si quantum dots is used to explain the charge storage and retention characteristics. Copyright © 2013 American Scientific Publishers All rights reserved.

Ma Zhongyuan;Liu Guanyuan;Jiang Xiaofan;Xia Guoying;Yan Minyi;Li Wei;Chen Kunji;Xu Ling;Xu Jun;Feng Duan

Journal of Nanoscience and Nanotechnology

2013

An nc-Si floating gate MOS structure is fabricated by thermal annealing of SiNx/a-Si/SiO2. There are nc-Si dots isolated by a-Si due to partial crystallization. Conductance-voltage (G - V) measurements are performed to investigate the effect of multiple interface states including Si-sub/SiO2, a-Si related (as-deposited sample) and nc-Si (annealed sample) in a charge trapping/releasing process. Double conductance peaks located in the depletion and weak inversion regions are found in our study. For the as-deposited sample, the Si-sub/SiO2 related G - V peak with weak intensity shifts to the negative as test frequency increases. The a-Si related G - V peak with strong intensity shifts slightly with the increasing frequency. For the annealed sample, little change appears in the intensity and shift of Si-sub/SiO2 related G - V peaks. The position of a-Si/nc-Si related peak is independent of frequency, and its intensity is weaker compared to that of the as-deposited sample. It is also found that as the size of nc-Si becomes larger, the a-Si/nc-Si related peak shifts to the depletion region due to the size effect of nc-Si. © 2013 Chinese Physical Society and IOP Publishing Ltd.

Shi Yong;Ma Zhong-Yuan;Chen Kun-Ji;Jiang Xiao-Fan;Li Wei;Huang Xin-Fan;Xu Ling;Xu Jun;Feng Duan

Chinese Physics Letters

2013

© 2014 Chinese Physical Society SiO x films (x = 1.3) are deposited on the silicon substrates by electron beam evaporation. The resistive switching behaviors from the device consisting of indium tin oxide (ITO)/SiO x /Si/Al with annealed SiO x layer as the resistive layer are investigated. It is found that on/off ratio of the device increases with the annealing temperature rising. The maximum on/off ratio reaches 10 ⁹ . The analyses of X-ray photoelectron spectrum and electron paramagnetic resonance spectrum reveal that the silicon dangling bonds in different valence states can be formed at different annealing temperatures, which is the main source of the conducting filament pathway. The result of ellipsometer indicates that the increase of refractive index of annealed SiO x film leads to the increase of the resistance of high resistance state.

Ren Sheng;Ma Zhong-Yuan;Jiang Xiao-Fan;Wang Yue-Fei;Xia Guo-Yin;Chen Kun-Ji;Huang Xin-Fan;Xu Jun;Xu Ling;Li Wei;Feng Duan

Wuli Xuebao Acta Physica Sinica

2014

© 2014 AIP Publishing LLC. Adding a resistive switching functionality to a silicon microelectronic chip is a new challenge in materials research. Here, we demonstrate that unipolar and electrode-independent resistive switching effects can be realized in the annealed Si-rich SiNx/SiNy multilayers with high on/off ratio of 10⁹. High resolution transmission electron microscopy reveals that for the high resistance state broken pathways composed of discrete nanocrystalline silicon (nc-Si) exist in the Si nitride multilayers. While for the low resistance state the discrete nc-Si regions is connected, forming continuous nc-Si pathways. Based on the analysis of the temperature dependent I-V characteristics and HRTEM photos, we found that the break-and-bridge evolution of nc-Si pathway is the origin of resistive switching memory behavior. Our findings provide insights into the mechanism of the resistive switching behavior in nc-Si films, opening a way for it to be utilized as a material in Si-based memories.

Jiang Xiaofan;Ma Zhongyuan;Yang Huafeng;Yu Jie;Wang Wen;Zhang Wenping;Li Wei;Xu Jun;Xu Ling;Chen Kunji;Huang Xinfan;Feng Duan

Journal of Applied Physics

2014

©2014 Optical Society of America A significant enhancement of blue light emission from amorphous oxidized silicon nitride (a-SiNx:O) films is achieved by introduction of ordered and size-controllable arrays of Ag nanoparticles between the silicon substrate and a-SiNx:O films. Using hexagonal arrays of Ag nanoparticles fabricated by nanosphere lithography, the localized surface plasmons (LSPs) resonance can effectively increase the internal quantum efficiency from 3.9% to 13.3%. Theoretical calculation confirms that the electromagnetic field-intensity enhancement is through the dipole surface plasma coupling with the excitons of a-SiNx:O films, which demonstrates a-SiNx:O films with enhanced blue emission are promising for silicon-based light-emitting applications by patterned Ag arrays.

Ma Zhongyuan;Ni Xiaodong;Zhang Wenping;Jiang Xiaofan;Yang Huafeng;Yu Jie;Wang Wen;Xu Ling;Xu Jun;Chen Kunji;Feng Duan

Optics Express

2014