APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

12 Apr 2010

Volume 96, Issue 15, Articles (15xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 96, 153701 (2010); http://dx.doi.org/10.1063/1.3385388 (3 pages)

Sinan Keten and Markus J. Buehler
Enlarge Image | Read More
Page 3 of 4 Pages Previous Page Next Page | Jump to Page
back to top
RSS Feeds

An optimization-based “phase field” model for polycrystalline ferroelectrics

F. X. Li, X. L. Zhou, and A. K. Soh

Appl. Phys. Lett. 96, 152905 (2010); http://dx.doi.org/10.1063/1.3377899 (3 pages) | Cited 5 times

Online Publication Date: 13 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An optimization-based computational model is proposed to study domain evolution in polycrystalline ferroelectrics composed of numerous grains, each of which consists of multiple domains. Domain switching is realized by an optimization process to minimize the free energy of each grain. Similar to phase field modeling, no priori domain-switching criterion is imposed in the proposed model. Moreover, by focusing on the volume fractions of domains only, the computational complexity of this model becomes much smaller and the domain textures evolution can be captured. Simulation results on both tetragonal and rhombohedral lead titanate zirconate ceramics illustrate the efficiency of this model.
Show PACS
77.80.Fm Switching phenomena
77.80.Dj Domain structure; hysteresis
77.84.Cg PZT ceramics and other titanates
65.40.G- Other thermodynamical quantities

Low temperature dielectric characterization of Mg-doped SrTiO3 thin films prepared by sol-gel

Olena Okhay, Aiying Wu, Paula M. Vilarinho, and Alexander Tkach

Appl. Phys. Lett. 96, 152906 (2010); http://dx.doi.org/10.1063/1.3360213 (3 pages) | Cited 2 times

Online Publication Date: 13 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Voltage dependence of dielectric constant ε′ of ferroelectrics and low dielectric loss tan δ of incipient ferroelectrics make them attractive for tuning elements in microwave circuits. In this letter, field dependence of the low-temperature dielectric permittivity and polarization of Mg-doped SrTiO3 films is studied. Incorporation of Mg on both Sr and Ti sites decreases the ε′ and relative tunability nr of sol-gel derived SrTiO3 films, whereas polarization is reduced by Ti site substitution only. tan δ of the studied films is ≤ 0.012, decreasing at low temperatures down to 0.001 when Ti is substituted by 5% of Mg.
Show PACS
77.55.-g Dielectric thin films
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.22.Gm Dielectric loss and relaxation
77.22.Ch Permittivity (dielectric function)
77.22.Ej Polarization and depolarization
77.80.-e Ferroelectricity and antiferroelectricity

Physical origin of dipole formation at high-k/SiO2 interface in metal-oxide-semiconductor device with high-k/metal gate structure

Xiaolei Wang, Kai Han, Wenwu Wang, Shijie Chen, Xueli Ma, Dapeng Chen, Jing Zhang, Jun Du, Yuhua Xiong, and Anping Huang

Appl. Phys. Lett. 96, 152907 (2010); http://dx.doi.org/10.1063/1.3399359 (3 pages) | Cited 9 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A physical model on dipole formation at high-k/SiO2 interface is proposed to study possible mechanism of flatband voltage (VFB) shift in metal-oxide-semiconductor device with high-k/metal gate structure. Dielectric contact induced gap states (DCIGS) on high-k or SiO2 side induced by high-k and SiO2 contact are assigned to dominant origin of dipole formation. DCIGS induced interface dipole is considered to cause VFB shift through charge transfer effect. Based on the proposed model, directions of dipoles at several high-k/SiO2 interfaces are predicted, and magnitudes of dipoles are approximately calculated. Both directions and magnitudes are in agreement with the reported results.
Show PACS
85.30.Tv Field effect devices
82.30.Fi Ion-molecule, ion-ion, and charge-transfer reactions
77.55.D- High-permittivity gate dielectric films

Origin and passivation of fixed charge in atomic layer deposited aluminum oxide gate insulators on chemically treated InGaAs substrates

Byungha Shin, Justin R. Weber, Rathnait D. Long, Paul K. Hurley, Chris G. Van de Walle, and Paul C. McIntyre

Appl. Phys. Lett. 96, 152908 (2010); http://dx.doi.org/10.1063/1.3399776 (3 pages) | Cited 24 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report experimental and theoretical studies of defects producing fixed charge within Al2O3 layers grown by atomic layer deposition (ALD) on In0.53Ga0.47As(001) substrates and the effects of hydrogen passivation of these defects. Capacitance-voltage measurements of Pt/ALD-Al2O3/n-In0.53Ga0.47As suggested the presence of positive bulk fixed charge and negative interfacial fixed charge within ALD-Al2O3. We identified oxygen and aluminum dangling bonds (DBs) as the origin of the fixed charge. First-principles calculations predicted possible passivation of both O and Al DBs, which would neutralize fixed charge, and this prediction was confirmed experimentally; postmetallization forming gas anneal removed most of the fixed charge in ALD-Al2O3.
Show PACS
81.65.Rv Passivation
81.05.Ea III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
71.55.Eq III-V semiconductors

Study on the electrical conduction mechanism of bipolar resistive switching TiO2 thin films using impedance spectroscopy

Min Hwan Lee, Kyung Min Kim, Gun Hwan Kim, Jun Yeong Seok, Seul Ji Song, Jung Ho Yoon, and Cheol Seong Hwang

Appl. Phys. Lett. 96, 152909 (2010); http://dx.doi.org/10.1063/1.3400222 (3 pages) | Cited 25 times

Online Publication Date: 16 April 2010

Full Text: Read Online (HTML) | Download PDF


See Also: Publisher's Note

Show Abstract
The electrical conduction mechanism within a resistive switching TiO2 film in its bipolar high resistance state was examined by ac impedance spectroscopy and dc current-voltage measurements. Bipolar switching, which can be initiated from a unipolar high resistance state, was attributed to both modulation of the Schottky barrier height at the film-electrode interface and the electronic energy state in the film. Numerical fittings of the impedance data revealed two distinct RC domains in series, which were attributed to an interfacial barrier (activation energy ∼ 0.1 eV) and a nonconducting layer (activation energy ∼ 0.5 eV), respectively.
Show PACS
73.61.Le Other inorganic semiconductors
72.60.+g Mixed conductivity and conductivity transitions
73.30.+y Surface double layers, Schottky barriers, and work functions
73.20.At Surface states, band structure, electron density of states
back to top
RSS Feeds

Pick, break, and placement of one-dimensional nanostructures for direct assembly and integration

Brian D. Sosnowchik, Jiyoung Chang, and Liwei Lin

Appl. Phys. Lett. 96, 153101 (2010); http://dx.doi.org/10.1063/1.3374879 (3 pages) | Cited 4 times

Online Publication Date: 12 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A direct, simple, and versatile assembly method for the manipulation of one-dimensional nanostructures and their integration with microscale devices has been demonstrated. Using a probe station with an unbiased tungsten probe, the facile process has been employed to accurately pick, break, and place individual titanium dioxide nanoswords and zinc oxide nanowires under a room-temperature, dry environment. The surface morphology of the nanostructures, probe tips, and adhesion forces were characterized. As such, the technique could enable the rapid assembly of individual nanostructures with complementary metal-oxide-semiconductor-compatible or complex microscale devices.
Show PACS
81.16.-c Methods of micro- and nanofabrication and processing
61.46.Km Structure of nanowires and nanorods (long, free or loosely attached, quantum wires and quantum rods, but not gate-isolated embedded quantum wires)
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
68.35.bg Semiconductors
81.07.Gf Nanowires
81.07.Vb Quantum wires

Production of carbonaceous nanostructures from a silver-carbon ambient spark

Jeong Hoon Byeon and Jang-Woo Kim

Appl. Phys. Lett. 96, 153102 (2010); http://dx.doi.org/10.1063/1.3396188 (3 pages) | Cited 7 times

Online Publication Date: 14 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using silver-carbon ambient sparks, hollow carbon nanospheres or multiwall carbon nanotubes were produced separately from carbon encapsulated silver nanoparticles (−1,400 K s−1) during relatively slow (−800 K s−1) or fast (−2,900 K s−1) cooling process. Different cooling processes (i.e., different exposures within high temperature) caused the formation of different carbon precipitates in the process of silver mediated graphitization: for −2,900 K s−1 and <−1,400 K s−1, respectively, obtained tubelike and sphere (encapsulated and hollow)-like carbonaceous nanostructures.
Show PACS
81.07.De Nanotubes
61.46.Fg Nanotubes
61.46.Df Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)
81.07.Bc Nanocrystalline materials
52.77.-j Plasma applications

Crystal symmetry breaking in few-quintuple Bi2Te3 films: Applications in nanometrology of topological insulators

K. M. F. Shahil, M. Z. Hossain, D. Teweldebrhan, and A. A. Balandin

Appl. Phys. Lett. 96, 153103 (2010); http://dx.doi.org/10.1063/1.3396190 (3 pages) | Cited 34 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report results of micro-Raman spectroscopy investigation of mechanically exfoliated single-crystal bismuth telluride films with thickness ranging from a few-nanometers to bulk limit. It is found that the optical phonon mode A1u, which is not-Raman active in bulk Bi2Te3 crystals, appears in the atomically-thin films due to crystal-symmetry breaking. The intensity ratios of the out-of-plane A1u and A1g modes to the in-plane Eg mode grow with decreasing film thickness. The evolution of Raman signatures with the film thickness can be used for identification of Bi2Te3 crystals with the thickness of few-quintuple layers important for topological insulator and thermoelectric applications.
Show PACS
61.50.Ah Theory of crystal structure, crystal symmetry; calculations and modeling
78.66.Bz Metals and metallic alloys
78.30.Er Solid metals and alloys
63.20.-e Phonons in crystal lattices

Photoelectric performance of TiO2 nanotube array photoelectrodes cosensitized with CdS/CdSe quantum dots

Xian-Feng Gao, Wen-Tao Sun, Guo Ai, and Lian-Mao Peng

Appl. Phys. Lett. 96, 153104 (2010); http://dx.doi.org/10.1063/1.3386525 (3 pages) | Cited 16 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The photoresponse of TiO2 nanotube-array films in the visible region is shown to have been significantly improved by sensitizing them with CdS and CdSe semiconductor quantum dots using a sequential chemical bath deposition method. These quantum dots served as cosensitizers, and the performance of corresponding photoelectrode was measured in a photoelectrochemical solar cell. A 13.0 mA/cm2 short circuit current density is achieved with the TiO2/CdS/CdSe photoelectrode under AM 1.5G illuminations, which is higher than the direct sum of CdS and CdSe sensitized TiO2.
Show PACS
88.40.J- Types of solar cells
88.40.hj Efficiency and performance of solar cells
82.45.Fk Electrodes
82.47.Jk Photoelectrochemical cells, photoelectrochromic and other hybrid electrochemical energy storage devices
84.60.Jt Photoelectric conversion

In situ x-ray diffraction study of graphitic carbon formed during heating and cooling of amorphous-C/Ni bilayers

K. L. Saenger, J. C. Tsang, A. A. Bol, J. O. Chu, A. Grill, and C. Lavoie

Appl. Phys. Lett. 96, 153105 (2010); http://dx.doi.org/10.1063/1.3397985 (3 pages) | Cited 10 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We examine graphitization of amorphous carbon (a-C) in a-C/Ni bilayer samples having the structure Si/SiO2/a-C(3–30 nm)/Ni(100 nm). In situ x-ray diffraction (XRD) measurements during heating in He at 3 °C/s to 1000 °C showed graphitic C formation beginning at temperatures T of 640–730 °C, suggesting graphitization by direct metal-induced crystallization, rather than by a dissolution/precipitation mechanism in which C is dissolved during heating and expelled from solution upon cooling. We also find that graphitic C, once formed, can be reversibly dissolved by heating to T>950 °C, and that nongraphitic C can be volatilized by annealing in H2-containing ambients.
Show PACS
81.05.uf Graphite

Confinement in PbSe wires grown by rf magnetron sputtering

Hyeson Jung, Rade Kuljic, Michael A. Stroscio, and Mitra Dutta

Appl. Phys. Lett. 96, 153106 (2010); http://dx.doi.org/10.1063/1.3400215 (3 pages) | Cited 3 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Lead selenide (PbSe) nanowires were grown by magnetron sputtering on silicon with silicon dioxide (SiO2/Si) substrates, and characterized by scanning electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, photoluminescence, and x-ray photoelectron spectroscopy. Closely packed PbSe nanowires of approximately 100 nm diameter grew in the 〈111〉 rock-salt cubic structure orientation. These large wires showed a large blueshift in the luminescence and absorption compared to the bulk crystal, demonstrating quantum confinement. This is attributed to a strong built-in field due to surface states, band bending, and a depletion layer which confines the carrier states.
Show PACS
81.15.Cd Deposition by sputtering
68.55.A- Nucleation and growth
78.30.-j Infrared and Raman spectra
68.65.La Quantum wires (patterned in quantum wells)
61.46.Km Structure of nanowires and nanorods (long, free or loosely attached, quantum wires and quantum rods, but not gate-isolated embedded quantum wires)
81.07.Gf Nanowires

Light detection enhanced by surface plasmon resonance in metal film

Mitsuo Fukuda, Takuma Aihara, Kenzo Yamaguchi, Yu Y. Ling, Kazuma Miyaji, and Makoto Tohyama

Appl. Phys. Lett. 96, 153107 (2010); http://dx.doi.org/10.1063/1.3402771 (3 pages) | Cited 6 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Light detection enhanced by surface plasmons was confirmed in Au film/n-type Si Schottky structures. Electrons excited directly with light in Au film overflowed into the n-type silicon, and this excitation was enhanced by surface plasmons induced by Au nanorods attached to the Au film. Excitation was clearly observed in a wavelength range corresponding to the energy of less than the band gap of silicon. The feasibility of Schottky-type photodiodes, in which electrons were never generated by absorption in semiconductors but directly excited in metal, was experimentally demonstrated.
Show PACS
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
85.30.Kk Junction diodes
85.60.Dw Photodiodes; phototransistors; photoresistors

Fabrication of silicon nanopillar-based nanocapacitor arrays

Shih-wei Chang, Jihun Oh, Steven T. Boles, and Carl V. Thompson

Appl. Phys. Lett. 96, 153108 (2010); http://dx.doi.org/10.1063/1.3374889 (3 pages) | Cited 8 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the fabrication of silicon nanopillar-based nanocapacitor arrays using metal-assisted etching in conjunction with electrodeposition. The high aspect ratio made possible by the catalyzed etching provides for an increased effective electrode area and hence a significant improvement in the capacitance density. Electroplated Ni electrode forms a conformal layer over the silicon nanopillars. Capacitance measurements show the expected trend as a function of pillar height and array period. The fabrication approach is simple, compatible with integration into standard silicon technology, and easily scalable.
Show PACS
84.32.Tt Capacitors
85.35.-p Nanoelectronic devices
81.16.-c Methods of micro- and nanofabrication and processing
81.65.Cf Surface cleaning, etching, patterning
81.15.Pq Electrodeposition, electroplating
back to top
RSS Feeds
FREE

Polarization-independent multiple selective reflections from bichiral liquid crystal films

Na Young Ha, Soon Moon Jeong, Suzushi Nishimura, and Hideo Takezoe

Appl. Phys. Lett. 96, 153301 (2010); http://dx.doi.org/10.1063/1.3393996 (3 pages) | Cited 3 times

Online Publication Date: 12 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have demonstrated polarization-independent multiple reflections covering overall visible region from a bichiral liquid crystal (LC) film with both chiral structures. The bichiral LC film was fabricated by an all-solution process using left-handed and right-handed polymeric cholesteric liquid crystal (CLC) films with a single pitch and an isotropic polymer film. The multiple reflections exceeding 50% reflectance were clearly observed at various polarizations of normally incident light. This characteristic can extend practical applications of CLCs to polarization-independent devices over broad-band regions.
Show PACS
61.30.Vx Polymer liquid crystals
78.40.Dw Liquids
42.70.Df Liquid crystals
78.66.Qn Polymers; organic compounds
78.15.+e Optical properties of fluid materials, supercritical fluids and liquid crystals
68.15.+e Liquid thin films
FREE

Dual carrier traps related hysteresis in organic inverters with polyimide-modified gate-dielectrics

Wei-Yang Chou and Bo-Liang Yeh

Appl. Phys. Lett. 96, 153302 (2010); http://dx.doi.org/10.1063/1.3395389 (3 pages) | Cited 2 times

Online Publication Date: 13 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We integrated pentacene- and NN′-diheptyl-3,4,9,10-perylenebiscarboximide-based transistors into an organic complementary metal oxide semiconductor (O-CMOS) whose gate-dielectric surface was modified by polyimide (PI). The hysteresis behaviors in metal-oxide-semiconductors, field-effect transistors, and O-CMOS were reported clearly. Measurements of hysteresis showed that the PI exhibited high trapping and detrapping speeds for charge carriers, including holes and electrons, to result in high performance transistors and O-CMOSs; moreover, the trapping and detrapping speeds were matched. Finally, a PI-modified organic inverter with little hysteresis, low static power dissipation, high noise margins, and switching voltage near VDD/2 was achieved simultaneously.
Show PACS
85.30.Tv Field effect devices
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
FREE

Reversible tuning of photonic crystal cavities using photochromic thin films

Deepak Sridharan, Edo Waks, Glenn Solomon, and John T. Fourkas

Appl. Phys. Lett. 96, 153303 (2010); http://dx.doi.org/10.1063/1.3377910 (3 pages) | Cited 9 times

Online Publication Date: 14 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate reversible tuning of a photonic crystal cavity resonance using a thin photochromic film composed of spiropyran and polymethylmethacrylate that serves as a photosensitive cladding layer. Exposure of spiropyran to ultraviolet light results in smooth redshift of the cavity resonance that can be reversed by exposure to visible wavelength light. We achieve a reversible resonance shift of up to 2.7 nm, which can be performed locally on individual cavities. The resonance shift over multiple successive UV and visible light exposures is studied to determine the repeatability of the photochromic film.
Show PACS
42.82.Gw Other integrated-optical elements and systems
42.65.-k Nonlinear optics
82.50.-m Photochemistry
42.79.Wc Optical coatings
42.70.Qs Photonic bandgap materials
FREE

Ultimate quality factor of silica microtoroid resonant cavities

Xiaomin Zhang, Hong Seok Choi, and Andrea M. Armani

Appl. Phys. Lett. 96, 153304 (2010); http://dx.doi.org/10.1063/1.3398008 (3 pages) | Cited 8 times

Online Publication Date: 15 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Silica optical microcavities with quality (Q factors above 1×108 have applications throughout science and engineering. While both the microtoroid and microsphere resonant cavity have demonstrated Q>1×108, only the microsphere has surpassed 1×109. Surprisingly, the reason for this performance disparity is directly related to type of silicon substrate used in the fabrication process. In the present work, the theoretical Q of planar toroidal silica resonant cavities is calculated and compared to experimental results from a series of devices fabricated from oxide on doped silicon wafers. As predicted, the Q depends on the substrate dopant concentration.
Show PACS
42.25.Fx Diffraction and scattering
FREE

Improved light extraction efficiency of white organic light-emitting devices by biomimetic antireflective surfaces

Yunfeng Li, Feng Li, Junhu Zhang, Chunlei Wang, Shoujun Zhu, Huijun Yu, Zhanhua Wang, and Bai Yang

Appl. Phys. Lett. 96, 153305 (2010); http://dx.doi.org/10.1063/1.3396980 (3 pages) | Cited 19 times

Online Publication Date: 16 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
One simple method to increase the light extraction from white organic light-emitting devices by using biomimetic silica antireflective surfaces is demonstrated. A silica cone array was directly etched on the opposite side of the indium–tin–oxide coated fused silica substrate. The antireflective surfaces can dramatically suppress the reflection loss and increase the transmission of light over a large range of wavelength and a large field of view. Using such surfaces, the luminance efficiency of the device in the normal direction is increased by a factor of 1.4 compared to that of the device using flat silica substrate.
Show PACS
85.60.Jb Light-emitting devices
42.79.Wc Optical coatings
FREE

Improvement of electron injection in inverted bottom-emission blue phosphorescent organic light emitting diodes using zinc oxide nanoparticles

Hyunkoo Lee, Insun Park, Jeonghun Kwak, Do Y. Yoon, and Changhee Lee

Appl. Phys. Lett. 96, 153306 (2010); http://dx.doi.org/10.1063/1.3400224 (3 pages) | Cited 17 times

Online Publication Date: 16 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We fabricated highly efficient iridium(III) bis[(4,6-di-fluorophenyl)-pyridinato-N,C2′] picolinate doped inverted bottom-emission blue phosphorescent organic light-emitting diodes, with an electron injection layer of zinc oxide (ZnO) nanoparticles (NPs). The ZnO NPs layer lowers the turn-on voltage by about 4 V and significantly enhances the efficiency. The device with ZnO NPs shows peak efficiencies of 16.5 cd/A and 8.2%, about three times higher than those of the device without ZnO NPs. Since the ZnO NPs layer has a wide band gap, good electron transporting properties and low work function, it can be utilized as an effective electron injection layer with good transparency.
Show PACS
85.60.Jb Light-emitting devices
FREE

Embedded indium-tin-oxide nanoelectrodes for efficiency and lifetime enhancement of polymer-based solar cells

Peichen Yu, Chia-Hua Chang, Ming-Shin Su, Min-Hsiang Hsu, and Kung-Hwa Wei

Appl. Phys. Lett. 96, 153307 (2010); http://dx.doi.org/10.1063/1.3395395 (3 pages) | Cited 12 times

Online Publication Date: 16 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this paper, distinctive indium-tin-oxide (ITO) nanorods are employed to serve as buried electrodes for polymer-based solar cells. The embedded nanoelectrodes allow three-dimensional conducting pathways for low-mobility holes, offering a highly scaffolded cell architecture in addition to bulk heterojunctions. As a result, the power conversion efficiency of a polymer cell with ITO nanoelectrodes is increased to about 3.4% and 4.4% under one-sun and five-sun illumination conditions, respectively, representing an enhancement factor of up to ∼ 10% and 36% compared to a conventional counterpart. Also, the corresponding device lifetime is prolonged twice as much to about 110 min under five-sun illumination.
Show PACS
88.40.jr Organic photovoltaics
82.45.Fk Electrodes
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
81.16.Be Chemical synthesis methods
back to top
RSS Feeds

Plasmonic nanoparticle enhanced photocurrent in GaN/InGaN/GaN quantum well solar cells

Imogen M. Pryce, Daniel D. Koleske, Arthur J. Fischer, and Harry A. Atwater

Appl. Phys. Lett. 96, 153501 (2010); http://dx.doi.org/10.1063/1.3377900 (3 pages) | Cited 26 times

Online Publication Date: 12 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate enhanced external quantum efficiency and current-voltage characteristics due to scattering by 100 nm silver nanoparticles in a single 2.5 nm thick InGaN quantum well photovoltaic device. Nanoparticle arrays were fabricated on the surface of the device using an anodic alumina template masking process. The Ag nanoparticles increase light scattering, light trapping, and carrier collection in the III-N semiconductor layers leading to enhancement of the external quantum efficiency by up to 54%. Additionally, the short-circuit current in cells with 200 nm p-GaN emitter regions is increased by 6% under AM 1.5 illumination. AFORS-Het simulation software results were used to predict cell performance and optimize emitter layer thickness.
Show PACS
88.40.hj Efficiency and performance of solar cells
73.63.Hs Quantum wells
72.40.+w Photoconduction and photovoltaic effects
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
88.40.jm Thin film III-V and II-VI based solar cells

Single-crystal II-VI on Si single-junction and tandem solar cells

M. Carmody, S. Mallick, J. Margetis, R. Kodama, T. Biegala, D. Xu, P. Bechmann, J. W. Garland, and S. Sivananthan

Appl. Phys. Lett. 96, 153502 (2010); http://dx.doi.org/10.1063/1.3386529 (3 pages) | Cited 8 times

Online Publication Date: 12 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
CdTe is one of the leading materials used in solar photovoltaics. However, the maximum reported CdTe cell efficiencies are considerably lower than the theoretically expected efficiencies for the ∼ 1.48 eV CdTe band gap. We report a class of single crystal CdTe-based solar cells grown epitaxially on crystalline Si that show promise for enhancing the efficiency and greatly lowering the cost per watt of single-junction and multijunction solar cells. The current-voltage results for our CdZnTe on Si solar cells show open-circuit voltages significantly higher than previously reported for any II-VI cells and as close to the thermodynamic limit as the best III-V-based cells.
Show PACS
88.40.jm Thin film III-V and II-VI based solar cells
88.40.hj Efficiency and performance of solar cells

Oxygen-atmosphere heat treatment in spin-on doping process for improving the performance of crystalline silicon solar cells

Zhengxin Liu (劉正新), Hidetaka Takato (高遠秀尚), Chiho Togashi (富樫千穂), and Isao Sakata (坂田功)

Appl. Phys. Lett. 96, 153503 (2010); http://dx.doi.org/10.1063/1.3394005 (3 pages) | Cited 2 times

Online Publication Date: 14 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Spin-on doping of phosphorus has been investigated and applied for the emitter fabrication of crystalline Si solar cells. Heat treatment in oxygen atmosphere at relatively low temperature of 550 °C prior to phosphorus diffusion is proved effective for improving solar cell performance, showing a conversion efficiency enhancement of more than 0.2% absolute. Internal quantum efficiency measurements show obvious enhancements at both short and long-wavelength regions. Secondary ion mass spectroscopy and Infrared absorption analysis reveal reduced C impurities after the heat treatment, possibly caused by burning the organic residues in the coated dopant source layer.
Show PACS
88.40.jj Silicon solar cells
88.40.hj Efficiency and performance of solar cells
61.72.uf Ge and Si
66.30.H- Self-diffusion and ionic conduction in nonmetals

High work function transparent middle electrode for organic tandem solar cells

D. J. D. Moet, P. de Bruyn, and P. W. M. Blom

Appl. Phys. Lett. 96, 153504 (2010); http://dx.doi.org/10.1063/1.3387863 (3 pages) | Cited 15 times

Online Publication Date: 16 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The use of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) in combination with ZnO as middle electrode in solution-processed organic tandem solar cells requires a pH modification of the PEDOT:PSS dispersion. We demonstrate that this neutralization leads to a reduced work function of PEDOT:PSS, which does not affect the performance of polythiophene:fullerene solar cells, but results in a lower open-circuit voltage of devices based on a polyfluorene derivative with a higher ionization potential. The introduction of a thin layer of a perfluorinated ionomer recovers the anode work function and gives an open-circuit voltage of 1.92 V for a double junction polyfluorene-based solar cell.
Show PACS
88.40.jr Organic photovoltaics
73.30.+y Surface double layers, Schottky barriers, and work functions
73.50.Pz Photoconduction and photovoltaic effects

Temperature dependent properties of InSb and InAs nanowire field-effect transistors

Henrik A. Nilsson, Philippe Caroff, Claes Thelander, Erik Lind, Olov Karlström, and Lars-Erik Wernersson

Appl. Phys. Lett. 96, 153505 (2010); http://dx.doi.org/10.1063/1.3402760 (3 pages) | Cited 17 times

Online Publication Date: 16 April 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present temperature dependent electrical measurements on InSb and InAs nanowire field-effect transistors (FETs). The FETs are fabricated from InAs/InSb heterostructure nanowires, where one complete transistor is defined within each of the two segments. Both the InSb and the InAs FETs are n-type with good current saturation and low voltage operation. The off-current for the InSb FET shows a strong temperature dependence, which we attribute to a barrier lowering due to an increased band-to-band tunneling in the drain part of the channel.
Show PACS
85.30.Tv Field effect devices
81.07.Gf Nanowires
Page 3 of 4 Pages Previous Page Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close