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1.
Po‐Chun Chen Yu‐Chien Chiu Zhi‐Wei Zheng Chun‐Hu Cheng Yung‐Hsien Wu 《固体物理学:研究快报》2016,10(12):919-923
We reported the characteristics of p‐type tin‐oxide (SnO) thin film transistors (TFTs) upon illumination with visible light. Our p‐type TFT device using the SnO film as the active channel layer exhibits high sensitivity toward the blue‐light with a high light/dark read current ratio (Ilight/Idark) of 8.2 × 103 at a very low driven voltage of <3 V. Since sensing of blue‐light radiation is very critical to our eyes, the proposed p‐type SnO TFTs with high sensitivity toward the blue‐light show great potential for future blue‐light detection applications.
2.
Jing Wang Ningning Zu Xianfeng Hao Yuanhui Xu Zhiping Li Zhijian Wu Faming Gao 《固体物理学:研究快报》2014,8(9):776-780
Structural, electronic and magnetic properties of Sr2FeOsO6 have been revisited by using the first‐principle calculations. Semiconducting behavior is reproduced. The band gap is 0.09 eV from generalized gradient approximation (GGA) and 0.30 eV by considering both SOC and U, a bit larger than the experimental observed 0.125 eV. In the C‐type antiferromagnetic configuration, spin frustration is found by analysing the magnetic exchange parameters, explaining the experimental observed magnetic complexity.
3.
High‐temperature ferroelectricity and strong magnetoelectric effects in a hybrid organic–inorganic perovskite framework 下载免费PDF全文
Ying Tian Alessandro Stroppa Yi‐Sheng Chai Paolo Barone Manuel Perez‐Mato Silvia Picozzi Young Sun 《固体物理学:研究快报》2015,9(1):62-67
A Cu‐based organic–inorganic perovskite framework exhibits high‐temperature ferroelectricity with strong magnetoelectric effects. Both electric field control of magnetization and magnetic field control of polarization are realized. Theoretical calculations suggest that a new mechanism of hybrid improper ferroelectricity arising from the Jahn–Teller distortions of magnetic metal ions and tilting of the organic cations are responsible for the peculiar multiferroic behaviors.
4.
Kirill Arapov Kaarle Jaakkola Vladimir Ermolov Guy Bex Eric Rubingh Samiul Haque Henrik Sandberg Robert Abbel Gijsbertus de With Heiner Friedrich 《固体物理学:研究快报》2016,10(11):812-818
Despite the great promise of printed flexible electronics from 2D crystals, and especially graphene, few scalable applications have been reported so far that can be termed roll‐to‐roll compatible. Here we combine screen printed graphene with photonic annealing to realize radio‐frequency identification devices with a reading range of up to 4 meters. Most notably our approach leads to fatigue resistant devices showing less than 1% deterioration of electrical properties after 1000 bending cycles. The bending fatigue resistance demonstrated on a variety of technologically relevant plastic and paper substrates renders the material highly suitable for various printable wearable devices, where repeatable dynamic bending stress is expected during usage. All applied printing and post‐processing methods are compatible with roll‐to‐roll manufacturing and temperature sensitive flexible substrates providing a platform for the scalable manufacturing of mechanically stable and environmentally friendly graphene printed electronics.
5.
Lead‐free mesoscopic Cs2SnI6 perovskite solar cells using different nanostructured ZnO nanorods as electron transport layers 下载免费PDF全文
Xiaofeng Qiu Yanan Jiang Hailiang Zhang Zhiwen Qiu Shuai Yuan Ping Wang Bingqiang Cao 《固体物理学:研究快报》2016,10(8):587-591
Lead‐free and more air‐stable perovskite Cs2SnI6 absorber with a direct bandgap of 1.48 eV is synthesized via a modified solution process. Different nanostructured ZnO nanorod arrays as electron transport layers and hole blocking layers are grown by controlling the seed layer and used to fabricate mesoscopic perovskite solar cells with Cs2SnI6 as light absorber layer. The influences of ZnO seed layers and nanorod morphology on the device photovoltaic performance were also investigated. With careful control of ZnO nanorod length and pore size to ensure high loading of the Cs2SnI6 absorber, we achieved power conversion efficiency of near 1%.
6.
Phosphorus prefers three‐connected configurations due to its inequivalent sp3‐hybridization. In the past year, many quasi two‐dimensional three‐connected networks were proposed as possible phosphorene allotropes. In this Letter, a new quasi two‐dimensional three‐connected network is proposed as a new potential phosphorene allotrope (Hex‐star). Based on first‐principles method calculations, the structure, stability and electronic properties of Hex‐star were systematically investigated. Our results indicate that Hex‐star is dynamically stable and it is a semiconductor with quasi‐direct band gap of 1.81 eV based on HSE06 method. Perspective top view (left) and Magen–David‐like orthographic top view (right) of Hex‐star phosphorene.
7.
CuNi binary alloy catalyst for growth of nitrogen‐doped graphene by low pressure chemical vapor deposition 下载免费PDF全文
Remi Papon Kamal P. Sharma Rakesh D. Mahayavanshi Subash Sharma Riteshkumar Vishwakarma Mohamad Saufi Rosmi Toshio Kawahara Joseph Cline Golap Kalita Masaki Tanemura 《固体物理学:研究快报》2016,10(10):749-752
The CuNi binary alloy can be significant as a catalyst for nitrogen‐doped (N‐doped) graphene growth considering controllable solubility of both carbon and nitrogen atoms. Here, we report for the first time the possibility of synthesizing substitutional N‐doped bilayer graphene on the binary alloy catalyst. Raman spectroscopy, atomic force microscopy and transmission electron microscopy analysis confirm the growth of bilayer and few‐layer graphene domains. X‐ray photoelectron spectroscopy analysis shows the presence of around 5.8 at% of nitrogen. Our finding shows that large N‐doped bilayer graphene domains can be synthesized on the CuNi binary alloy.
8.
Mohammed J. Uddin Deborah E. Daramola Ever Velasquez Tarik J. Dickens Jin Yan Emily Hammel Federico Cesano Okenwa I. Okoli 《固体物理学:研究快报》2014,8(11):898-903
An innovative hybrid QD sensitized photovoltaic carbon nanotubes microyarn has been developed using thermally‐stable and highly conductive carbon nanotubes yarns (CNYs). These CNYs are highly inter‐aligned, ultrastrong and flexible with excellent electrical conductivity, mechanical integrity and catalytic properties. The CNYs are coated with a QD‐incorporated TiO2 microfilm and intertwined with a second set of CNYs as a counter electrode (CE). The maximum photon to current conversion efficiency (ηAM1.5) achieved with prolonged‐time stability was 5.93%. These cells are capable of efficiently harvesting incident photons regardless of direction and generating photocurrents with high efficiency and operational stability.
9.
Numerical modeling of photovoltaic efficiency of n‐type GaN nanowires on p‐type Si heterojunction 下载免费PDF全文
In this Letter, we investigate the photovoltaic properties of heterojunction solar cells based on n‐GaN nanowire (NW)/ p‐Si substrate heterostructures by means of numerical modeling. Antireflection properties of the NW array on the top of Si substrate were studied theoretically to show an order of magnitude enhancement in antireflection properties in comparison to the pure Si surface (2.5% vs. 33.8%). In order to determine the optimal morphology and doping levels of the structure with maximum possible efficiency we simulated its properties. The carried out simulation showed that the maximum efficiency should be more than 20% under AM1.5D illumination. The proposed design opens new perspectives and opportunities in the field of heterojunction tandem solar cell researches.
10.
Today's micro‐ and nano‐fabrication is essentially two‐dimensional, with very limited possibilities of accessing the third dimension. The most viable way to mass‐fabricate functional structures at the nano‐scale, such as electronics or MEMS, with equal feature sizes in all directions, is by three‐dimensional self‐assembly. Up to now, three‐dimensional self‐assembly has mainly been restricted to crystals of polymer spheres. We report on two‐ and three‐dimensional self‐assembly of silicon cubes, levitated in a paramagnetic fluid. We demonstrate the benefits of templating and study the effect of a change in hydrophilicity of the cubes. These experiments bring us one step closer to three‐dimensional self‐assembly of anisotropic, semiconducting units, which is a crucial milestone in overcoming the scaling limits imposed by contemporary 2D microfabrication.
11.
Polymer light‐emitting electrochemical cells (LECs) are two‐terminal, solid state devices with a mixed ionic/electronic conductor as the active layer. Once activated by a DC voltage or current, a doping‐induced homojunction dictates the electrical and optical response of the LEC, making it highly unique and attractive among organic devices. However, the depletion width, a fundamental parameter of any semiconductor homojunction, has never been determined experimentally for a static LEC junction. In this study, we apply spatially resolved photocurrent and photoluminescence (PL) scanning to an extremely large planar LEC that had been turned on to emit strongly then subsequently frozen. These concerted scanning and imaging studies depict a p–i–n junction structure in which the peak built‐in electric field lies at the interface between the intrinsic region and the p‐doped region. The corresponding 18 μm depletion width is very small compared to the 700 μm interelectrode spacing.
12.
Low leakage stoichiometric SrTiO3 dielectric for advanced metal–insulator–metal capacitors 下载免费PDF全文
Mihaela Popovici Ben Kaczer Valeri V. Afanas'ev Gabriele Sereni Luca Larcher Augusto Redolfi Sven Van Elshocht Malgorzata Jurczak 《固体物理学:研究快报》2016,10(5):420-425
Metal–insulator–metal capacitors (MIMCAP) with stoichiometric SrTiO3 dielectric were deposited stacking two strontium titanate (STO) layers, followed by intermixing the grain determining Sr‐rich STO seed layer, with the Ti‐rich STO top layer. The resulted stoichiometric SrTiO3 would have a structure with less defects as demonstrated by internal photoemission experiments. Consequently, the leakage current density is lower compared to Sr‐rich STO which allow further equivalent oxide thickness downscaling.
13.
Fabrication of transparent and flexible carbon‐doped ZnO field emission display on plastic substrate 下载免费PDF全文
Transparent and flexible carbon doped ZnO (C:ZnO) field emission device was successfully fabricated on an arylite substrate. Excellent adhesion of deposited C:ZnO on the flexible substrate was achieved with low sputtering power and Ar flow rate. In the fabricated device, nanostructured C:ZnO and as‐deposited thin films were used as field emitter and phosphor screen, respectively. The C:ZnO thin film showed a transparency of about 80% at 550 nm wavelength and average sheet resistance of 1.96 kΩ/□. The C:ZnO phosphor screen emitted red light during the field emission measurement, correlating the dominant cathodoluminescence peak at 646 nm. Thus, a promising transparent and flexible field emission display can be realized with C:ZnO based material.
14.
Whispering gallery modes in intrinsic TiO2 microspheres coupling to the defect‐related photoluminescence after visible excitation 下载免费PDF全文
Defect‐caused visible photoluminescence after visible excitation in anatase TiO2 microresonators couples to whispering gallery modes (WGMs). Spherical anatase TiO2 of a radius between 1.5 µm and 4 µm have been prepared by a sol–gel technique based on hydrolysis of titanium tetrabutoxide. The observation of WGMs in intrinsic anatase TiO2 without additional dopant offers new perspectives for the localisation of light at TiO2 surfaces for the design of photocatalysts.
15.
Sebastian Bommel Holger Spranger C. Weber N. Kleppmann Stephan V. Roth S. H. L. Klapp Stefan Kowarik 《固体物理学:研究快报》2015,9(11):646-651
Understanding and controlling the growth and stability of molecular thin films on solid surfaces is necessary to develop nanomaterials with well‐defined physical properties. As a prominent model system in organic electronics, we investigate the post‐growth dewetting kinetics of the fullerene C60 on mica with real‐time and in situ X‐ray scattering. After layer‐by‐layer growth of C60, we find a thermally‐activated post‐growth dewetting, where the smooth C60‐layer breaks up into islands. This clearly shows that growth is kinetically limited before the system moves over an activation barrier into an energetically favored configuration. From the temperature‐dependent dewetting kinetics we find an effective activation barrier of 0.33 eV, which describes both the temperature‐dependent macroscopic changes in the surface morphology and the microscopic processes of inter‐ and intralayer diffusion during dewetting.
16.
An observation of negative refraction in the naturally obtained composition of graphene and barium ferrite is reported. The capacitance and inductance measurements revealed the electric and magnetic resonances accompanied with the negative values of permittivity and permeability in the overlapped frequency range. According to the “left‐handed” media approach such a material is characterized by negative refraction. The derived values of the real part of refractive index are negative at the frequencies above 500 MHz.
17.
Microstructural identification of Cu in solar cells sensitive to light‐induced degradation 下载免费PDF全文
Light‐induced degradation (mc‐LID or LeTID) can lead to a severe efficiency loss in multi‐crystalline solar cells. The underlying mechanism clearly distinguishes from known mechanisms as B‐O‐LID and Fe‐B‐LID. Various defect models have been suggested for mc‐LID mainly based on metal impurities, including Cu which is known to cause light‐induced degradation. We investigate mc‐LID sensitive PERC cells that show an efficiency degradation of 15%rel. The weaker degradation of the grain boundaries (GBs) typical for mc‐LID is identified and further investigated from front and rear side with respect to recombination activities. The combination of local electrical measurements (LBIC), target preparation (REM, FIB) and element analysis (EDX, TEM) unveil Cu‐containing precipitates at the rear side of the solar cells. They accumulate at grain boundaries and at the rear surface of the Si‐bulk material where the passivation stack is damaged. We conclude that Cu originates from the cell material and discuss its relation to mc‐LID.
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19.
Jianyu Wang Huabin Sun Yun Sheng Fan Gao Yao Yin Yun Li Lijia Pan Youdou Zheng Yi Shi Takashi Sekiguchi 《固体物理学:研究快报》2015,9(8):466-469
Surface‐diffusion‐induced spontaneous Ga incorporation process is demonstrated in ZnO nanowires grown on GaN substrate. Crucially, contrasting distributions of Ga atoms in axial and radial directions are experimentally observed. Ga atoms uniformly distribute along the ~10 μm long ZnO nanowire and show a rapidly gradient distribution in the radial direction, which is attributed substantially to the difference between surface and volume diffusion. The understanding on the incorporation process can potentially modulate doping and properties in semiconductor nanomaterials.
20.
Sergei V. Zhukovsky Igor E. Protsenko Renat Sh. Ikhsanov Igor V. Smetanin Viktoriia E. Babicheva Alexander V. Uskov 《固体物理学:研究快报》2015,9(10):570-574
Transition absorption of a photon by an electron passing through a boundary between two media with different permittivities is described both classically and quantum mechanically. Transition absorption is shown to make a substantial contribution to photoelectron emission at a metal/semicon‐ductor interface in nanoplasmonic systems, and is put forth as a possible microscopic mechanism of the surface photoelectric effect in photodetectors and solar cells containing plasmonic nanoparticles.