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

23 Apr 2012

Volume 100, Issue 17, Articles (17xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 100, 171903 (2012); http://dx.doi.org/10.1063/1.4704193 (3 pages)

Y. Peng and K. Kempa
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

The impact of active layer thickness on low-frequency noise characteristics in InZnO thin-film transistors with high mobility

Hyun-Sik Choi, Sanghun Jeon, Hojung Kim, Jaikwang Shin, Changjung Kim, and U-In Chung

Appl. Phys. Lett. 100, 173501 (2012); http://dx.doi.org/10.1063/1.4705406 (4 pages)

Online Publication Date: 23 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigated low-frequency noise (LFN) characteristics in passivated InZnO thin-film transistors with various active layer thicknesses. These LFNs are matched to the mobility fluctuation model [F. N. Hooge, IEEE Trans. Electron Devices 41, 1926 (1994)]. According to this model, the Hooge’s parameter (αH) is significantly increased as the active layer thickness is decreased. By plotting the αH with the effective mobility (μeff), we found that the αH is proportional to the μeff−1. This indicates that the mobility fluctuation by the impurity scattering is significantly increased as the active layer thickness is decreased, and that is the main origin of the LFN increments in the thinner active-layer-thickness devices.
Show PACS
85.30.Tv Field effect devices

Polarization rotation under two-photon Raman resonance for magnetometry

S. Pradhan, R. Behera, and A. K. Das

Appl. Phys. Lett. 100, 173502 (2012); http://dx.doi.org/10.1063/1.4705424 (3 pages) | Cited 1 time

Online Publication Date: 23 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The polarization rotation and coherent population trapping signal arising due to two photon process using linearly polarized light are found to be significantly enhanced for a Zeeman degenerate system. The zero crossing of the dispersive profile is found to be shifting proportional to the applied magnetic field, albeit the absorptive profile position remains invariant for a slightly imbalanced orthogonal circular polarization component. It provides an alternative method for precise measurement of vector magnetic field without requirement of a bias field. The use of polarization rotation signal for magnetic field measurement offers added advantage due to improved signal to noise ratio.
Show PACS
07.55.Ge Magnetometers for magnetic field measurements
32.60.+i Zeeman and Stark effects
32.80.-t Photoionization and excitation
42.25.Ja Polarization

The contribution of narrow band and modulation of thermoelectric performance in doped layered cobaltites Bi2Sr2Co2Oy

L. H. Yin, R. Ang, Y. N. Huang, H. B. Jiang, B. C. Zhao, X. B. Zhu, W. H. Song, and Y. P. Sun

Appl. Phys. Lett. 100, 173503 (2012); http://dx.doi.org/10.1063/1.4705429 (4 pages) | Cited 4 times

Online Publication Date: 23 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have performed the temperature dependence of resistivity ρ(T) and thermoelectric power S(T) by a series of doping in layered cobaltites Bi2Sr2Co2Oy. For all samples, a metallic ρ(T) behavior and a large temperature-independent S is observed at higher temperatures, while we found a upturning ρ(T) but without corresponding variation of S(T) at lower temperatures. The present results strongly demonstrate the contribution of narrow band. Moreover, the doping could effectively modulate the thermoelectric performance. Especially for Bi2Sr1.9Ca0.1Co2Oy, it may provide an excellent platform to be a promising candidate of thermoelectric materials.
Show PACS
72.20.Pa Thermoelectric and thermomagnetic effects
72.80.Sk Insulators
71.28.+d Narrow-band systems; intermediate-valence solids

Effect of doping concentration of substrate silicon on retention characteristics in metal-ferroelectric-insulator-semiconductor capacitors

Y. G. Xiao, Y. Xiong, M. H. Tang, J. C. Li, C. P. Cheng, B. Jiang, Z. H. Tang, X. S. Lv, H. Q. Cai, X. C. Gu, and Y. C. Zhou

Appl. Phys. Lett. 100, 173504 (2012); http://dx.doi.org/10.1063/1.4704983 (4 pages)

Online Publication Date: 23 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The polarization retention characteristics in metal-ferroelectric-insulator-semiconductor (MFIS) capacitor was theoretically investigated by considering depolarization field based on Lou’s polarization retention model [J. Appl. Phys. 105(9), 094107 (2009)]. The derived results demonstrated that the retention property can be effectively improved by enhancing the doping concentration of substrate silicon. Additionally, it is better to keep the MFIS capacitor at accumulation and depletion regions than at inversion region for improving the polarization retention property. It is expected that this investigation may offer some useful guidelines to the design and retention property improvement of MFIS capacitor and other MFIS structure devices.
Show PACS
84.32.Tt Capacitors
85.50.-n Dielectric, ferroelectric, and piezoelectric devices

Thermal stability of magnetoelectric sensors

Ying Shen, Junqi Gao, Yaojin Wang, Jiefang Li, and Dwight Viehland

Appl. Phys. Lett. 100, 173505 (2012); http://dx.doi.org/10.1063/1.4705298 (3 pages) | Cited 5 times

Online Publication Date: 23 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effect of temperature on the equivalent magnetic noise floor of Metglas-Pb(Zr,Ti)O3 (PZT) laminate magnetoelectric (ME) sensors has been investigated in the temperature range of −50 °C to 50 °C. In detail, the parameters that control the noise floor of ME sensors, such as capacitance, tan δ, and ME charge coefficient, were characterized. The results show the noise floor was thermally stable around 30 pT/√Hz (f = 1 Hz) over the studied temperature range. To demonstrate the relative invariance of ME sensor at different temperatures over the range studied, a simulation based on a noise model was conducted, where the predicted and measured equivalent magnetic noise floors were found to well agree.
Show PACS
85.80.Jm Magnetoelectric devices

A permendur-piezoelectric multiferroic composite for low-noise ultrasensitive magnetic field sensors

G. Sreenivasulu, U. Laletin, V. M. Petrov, V. V. Petrov, and G. Srinivasan

Appl. Phys. Lett. 100, 173506 (2012); http://dx.doi.org/10.1063/1.4705305 (4 pages) | Cited 2 times

Online Publication Date: 23 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Low-frequency and resonance magnetoelectric (ME) effects have been studied for a trilayer of permendur (alloy of Fe-Co-V) and lead zirconate titanate (PZT). The high permeability and high magnetostriction for permendur, key ingredients for magnetic field confinement, and ME response result in ME voltage coefficient of 23 V/cm Oe at low-frequency and 250 V/cm Oe at electromechanical resonance (EMR) for a sample with PZT fibers and inter-digital-electrodes. Theoretical ME coefficients are in agreement with the data. Measured magnetic noise floor of 25 pT/√Hz at 1 Hz and 100 fT/√Hz at EMR are comparable to best values reported for Metglas-PZT fiber sensors.
Show PACS
75.80.+q Magnetomechanical effects, magnetostriction
85.75.Ss Magnetic field sensors using spin polarized transport
77.65.-j Piezoelectricity and electromechanical effects
77.84.Lf Composite materials
77.55.Nv Multiferroic/magnetoelectric films
75.85.+t Magnetoelectric effects, multiferroics

Charge trap flash memory using ferroelectric materials as a blocking layer

Yujeong Seo, Ho-Myoung An, Min Yeong Song, and Tae Geun Kim

Appl. Phys. Lett. 100, 173507 (2012); http://dx.doi.org/10.1063/1.4705411 (4 pages)

Online Publication Date: 24 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this paper, we propose a charge-trap flash memory device using a ferroelectric material, Sr0.7Bi2.3Nb2O9 (SBN), with spontaneous polarization as a blocking layer. This device consists of metal/SBN/nitride/oxide/silicon and has an advantage in the carrier injection into the nitride from the silicon due to polarization charges formed in the ferroelectric material. Compared to conventional metal/oxide/nitride/oxide/silicon memory devices, the proposed devices showed a larger memory window (7 V), faster program/erase (P/E) speeds (100/500 μs), and higher endurance (105 P/E cycles) with comparable retention properties.
Show PACS
84.30.Sk Pulse and digital circuits
85.50.Gk Non-volatile ferroelectric memories

Experimental evidence for the correlation between the weak inversion hump and near midgap states in dielectric/InGaAs interfaces

Igor Krylov, Lior Kornblum, Arkady Gavrilov, Dan Ritter, and Moshe Eizenberg

Appl. Phys. Lett. 100, 173508 (2012); http://dx.doi.org/10.1063/1.4704925 (4 pages) | Cited 4 times

Online Publication Date: 24 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Temperature dependent capacitance–voltage (C-V) and conductance-voltage (G-V) measurements were performed to obtain activation energies (EA) for weak inversion C-V humps and parallel conductance peaks in Al2O3/InGaAs and Si3N4/InGaAs gate stacks. Values of 0.48 eV (slightly more than half of the band gap of the studied In0.53Ga0.47As) were obtained for EA of both phenomena for both gate dielectrics studied. This indicates an universal InGaAs behavior and shows that both phenomena are due to generation-recombination of minority carriers through near midgap located interface states. The C-V hump correlates with the interface states density (Dit) and can be used as a characterization tool for dielectric/InGaAs systems.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Electrical and reliability characteristics of polycrystalline silicon thin-film transistors with high-κ Eu2O3 gate dielectrics

Li-Chen Yen, Chia-Wei Hu, Tsung-Yu Chiang, Tien-Sheng Chao, and Tung-Ming Pan

Appl. Phys. Lett. 100, 173509 (2012); http://dx.doi.org/10.1063/1.4705472 (3 pages) | Cited 1 time

Online Publication Date: 25 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this study, we developed a high-performance low-temperature polycrystalline silicon thin-film transistor (LTPS-TFT) incorporating an ultra thin Eu2O3 gate dielectric. High-κ Eu2O3 LTPS-TFT annealed at 500 °C exhibits a low threshold voltage of 0.16 V, a high effective carrier mobility of 44 cm2/V-s, a small subthreshold swing of 142 mV/decade, and a high Ion/Ioff current ratio of 1.34 × 107. These significant improvements are attributed to the high gate-capacitance density due to the adequate quality of Eu2O3 gate dielectric with small interfacial layer of effective oxide thickness of 2.5 nm. Furthermore, the degradation mechanism of positive bias temperature instability was studied for a high-k Eu2O3 LTPS-TFT device.
Show PACS
85.30.Tv Field effect devices

Direct evidence of current blocking by ZnSe in Cu2ZnSnSe4 solar cells

Jörn Timo Wätjen, Jessica Engman, Marika Edoff, and Charlotte Platzer-Björkman

Appl. Phys. Lett. 100, 173510 (2012); http://dx.doi.org/10.1063/1.4706256 (3 pages) | Cited 7 times

Online Publication Date: 25 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Thin films of polycrystalline Cu2ZnSnSe4 were made by selenization of co-sputtered metallic precursors and processed to solar cells. Electron beam induced current (EBIC) in combination with microscopic scale IV characterization is used to investigate lateral inhomogeneities in electrical performance across the solar cell area. Transmission electron microscopy relates areas with low EBIC response to the formation of a ZnSe phase at the absorber surface resulting in a current blocking behavior and a reduced short-circuit current density for the solar cells. Areas without ZnSe have a high EBIC response and result in high quality diodes well suited for solar cells.
Show PACS
88.40.hj Efficiency and performance of solar cells
73.61.Le Other inorganic semiconductors
68.55.ag Semiconductors
81.15.Cd Deposition by sputtering
88.40.jn Thin film Cu-based I-III-VI2 solar cells

Narrow-band long-/very-long wavelength two-color type-II InAs/GaSb superlattice photodetector by changing the bias polarity

Yanhua Zhang, Wenquan Ma, Yang Wei, Yulian Cao, Jianliang Huang, Kai Cui, and Xiaolu Guo

Appl. Phys. Lett. 100, 173511 (2012); http://dx.doi.org/10.1063/1.4707162 (4 pages) | Cited 1 time

Online Publication Date: 25 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on a narrow-band two-color photodetector using type-II InAs/GaSb superlattices (SLs) in the long-/very-long wavelength infrared (VLWIR) ranges by changing the polarity of the bias. The narrow-band photoresponse is achieved by sequentially growing the doped SL structure that has a shorter cutoff wavelength as a low-pass filter for the absorption layers that has a longer cutoff wavelength. At 77 K, the 50% cutoff wavelength of the photodiode is 10 μm when the applied bias voltage is –0.1 V and is 16 μm at +40 mV. The δλ/λ is 44% for the LWIR band and is 46% for the VLWIR band.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.60.Dw Photodiodes; phototransistors; photoresistors

Near-infrared sensitization of solid-state dye-sensitized solar cells with a squaraine dye

Amalie Dualeh, Jared H. Delcamp, Mohammad K. Nazeeruddin, and Michael Grätzel

Appl. Phys. Lett. 100, 173512 (2012); http://dx.doi.org/10.1063/1.4707374 (4 pages) | Cited 2 times

Online Publication Date: 26 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Here, we report the use of a squaraine-based dye, JD10, as a near-infrared sensitizer for solid-state dye-sensitized solar cells (ssDSCs). Using spiro-MeOTAD as a hole-transport material, JD10 gave the highest reported power conversion efficiencies (PCE), 3.16% for squaraine-based ssDSCs. The photocurrent was further enhanced by co-sensitization with the organic D-π-A dye D35, increasing the light harvested leading to a PCE to 4.42%.
Show PACS
88.40.jr Organic photovoltaics
88.40.hj Efficiency and performance of solar cells

Probing and modelling the localized self-mixing in a GaN/AlGaN field-effect terahertz detector

J. D. Sun (孙建东), H. Qin (秦华), R. A. Lewis, Y. F. Sun (孙云飞), X. Y. Zhang (张晓渝), Y. Cai (蔡勇), D. M. Wu (吴东岷), and B. S. Zhang (张宝顺)

Appl. Phys. Lett. 100, 173513 (2012); http://dx.doi.org/10.1063/1.4705306 (4 pages)

Online Publication Date: 26 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In our previous work [Sun et al., Appl. Phys. Lett. 100, 013506 (2012)], we inferred the existence of localized self-mixing in an antenna-coupled field-effect terahertz detector. In this Letter, we report a quasistatic self-mixing model taking into account the localized terahertz fields and its verification by comparing the simulated results with the experimental data in a two-dimensional space of the gate voltage and the drain/source bias. The model well describes the detector characteristics: not only the magnitude, but also the polarity, of the photocurrent can be tuned. The existence of strongly localized self-mixing in such detectors is confirmed.
Show PACS
85.30.Tv Field effect devices
84.40.Ba Antennas: theory, components and accessories
07.57.Pt Submillimeter wave, microwave and radiowave spectrometers; magnetic resonance spectrometers, auxiliary equipment, and techniques

N-channel carbon nanotube enabled vertical field effect transistors with solution deposited ZnO nanoparticle based channel layers

Po-Hsiang Wang, Bo Liu, Yu Shen, Ying Zheng, Mitchell A. McCarthy, Paul Holloway, and Andrew G. Rinzler

Appl. Phys. Lett. 100, 173514 (2012); http://dx.doi.org/10.1063/1.4709618 (3 pages)

Online Publication Date: 27 April 2012

Full Text: Read Online (HTML) | Download PDF

Show Abstract
N-channel carbon nanotube enabled vertical field effect transistors (CN-VFETs) exploiting a solution deposited ZnO nanoparticle thin film as the channel material are demonstrated. Transistor performance benefits from a thermal anneal followed by an oxygen plasma treatment. The devices exhibit on/off ratios approaching 104 with output current densities exceeding 60 mA/cm2. Combined with p-channel organic CN-VFETs, the solution based processing could allow for the development of low-cost complementary circuits.
Show PACS
85.30.Tv Field effect devices
85.35.Kt Nanotube devices
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close