scholarly journals Surface Acoustic Wave-Induced Electroluminescence Intensity Oscillation in Planar Light-Emitting Devices

2005 ◽  
Vol 869 ◽  
Author(s):  
Marco Cecchini ◽  
Vincenzo Piazza ◽  
Fabio Beltram ◽  
Martin Ward ◽  
Andrew Shields ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Photon Counting ◽  
Type Region ◽  
Light Emitting ◽  
Intensity Oscillation ◽  
Light Emitting Devices ◽  
Electroluminescence Intensity ◽  
P Type ◽  
Wave Induced

AbstractElectroluminescence (EL) emission controlled by means of surface acoustic waves (SAWs) in planar light-emitting diodes (pLEDs) is demonstrated. Interdigital transducers (IDTs) for SAW generation were integrated onto pLEDs fabricated following a scheme compatible with SAW propagation [1]. EL in presence of SAW was studied by time-correlated photon-counting techniques. We found intensity oscillation at the SAW frequency (˜1 GHz) demonstrating electron injection into the p-type region synchronous with the SAW wavefronts.

scholarly journals Surface acoustic wave-induced electroluminescence intensity oscillation in planar light-emitting devices

2005 ◽  
Vol 86 (24) ◽  
pp. 241107 ◽  
Author(s):  
Marco Cecchini ◽  
Vincenzo Piazza ◽  
Fabio Beltram ◽  
D. G. Gevaux ◽  
M. B. Ward ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Light Emitting ◽  
Intensity Oscillation ◽  
Light Emitting Devices ◽  
Electroluminescence Intensity ◽  
Wave Induced

scholarly journals Generation and enhancement of surface acoustic waves on a highly doped p-type GaAs substrate

2019 ◽  
Vol 1 (9) ◽  
pp. 3537-3546 ◽  
Author(s):  
Boqun Dong ◽  
Mona E. Zaghloul
Keyword(s):  
Acoustic Waves ◽  
Gaas Substrate ◽  
Surface Acoustic Waves ◽  
P Type

Enhancement of SAWs propagating along the surface of a highly doped p-type GaAs substrate is achieved using a ZnO/SiO2 island.

scholarly journals Enhancement of Photoemission on p-Type GaAs Using Surface Acoustic Waves

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2419
Author(s):  
Boqun Dong ◽  
Andrei Afanasev ◽  
Rolland Johnson ◽  
Mona Zaghloul
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Device Fabrication ◽  
Effective Lifetime ◽  
Additional Layer ◽  
Carrier Recombination ◽  
Multiphysics Simulations ◽  
Current Voltage ◽  
Piezoelectric Fields ◽  
P Type

We demonstrate that photoemission properties of p-type GaAs can be altered by surface acoustic waves (SAWs) generated on the GaAs surface due to dynamical piezoelectric fields of SAWs. Multiphysics simulations indicate that charge-carrier recombination is greatly reduced, and electron effective lifetime in p-doped GaAs may increase by a factor of 10× to 20×. It implies a significant increase, by a factor of 2× to 3×, of quantum efficiency (QE) for GaAs photoemission applications, like GaAs photocathodes. Conditions of different SAW wavelengths, swept SAW intensities, and varied incident photon energies were investigated. Essential steps in SAW device fabrication on a GaAs substrate are demonstrated, including deposition of an additional layer of ZnO for piezoelectric effect enhancement, measurements of current–voltage (I–V) characteristics of the SAW device, and ability to survive high-temperature annealing. Results obtained and reported in this study provide the potential and basis for future studies on building SAW-enhanced photocathodes, as well as other GaAs photoelectric applications.

Active-Nitrogen-Doped P-Type ZnSe Grown by Gas-Source Molecular Beam Epitaxy for Blue-Light-Emitting Devices

1993 ◽  
Vol 32 (Part 2, No. 12A) ◽  
pp. L1725-L1727 ◽  
Author(s):  
Masayuki Imaizumi ◽  
Yasuyuki Endoh ◽  
Ken-ichi Ohtsuka ◽  
Toshiro Isu ◽  
Masahiro Nunoshita
Keyword(s):  
Molecular Beam Epitaxy ◽  
Blue Light ◽  
Molecular Beam ◽  
Active Nitrogen ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Nitrogen Doped ◽  
Gas Source ◽  
P Type

All-inorganic Light Emitting Devices Based on Semiconducting Nanoparticles

2010 ◽  
Vol 1260 ◽  
Author(s):  
Ekaterina Neshataeva ◽  
Tilmar Kümmell ◽  
André Ebbers ◽  
Gerd Bacher
Keyword(s):  
Spectral Range ◽  
Zno Nanoparticles ◽  
Hole Injection ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Layer Sequence ◽  
Current Densities ◽  
The Stability ◽  
P Type ◽  
Device Operation

AbstractWe demonstrate light emitting devices based on ZnO nanoparticles and realized without any additional organic support layers. Pure ZnO devices showed electroluminescence in the visible and the UV spectral range at voltages below 10 V. In order to facilitate hole injection and to stabilize device operation, additional p-type inorganic support layers were introduced. Sputtered NiO layers are shown to improve the stability of the device and its I/V behavior. First bilayer devices consisting of a layer sequence of p-doped Si and naturally n-doped ZnO nanoparticles revealed promising electro-luminescence results with a high contribution in the UV spectral range at reduced current densities.

scholarly journals Hole Injection Role of p-Type Conjugated Polymer Nanolayers in Phosphorescent Organic Light-Emitting Devices

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2283
Author(s):  
Sooyong Lee ◽  
Hwajeong Kim ◽  
Youngkyoo Kim
Keyword(s):  
Thermal Annealing ◽  
Annealing Time ◽  
Conjugated Polymer ◽  
Hole Injection ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices ◽  
P Type

Here, we report the hole injection role of p-type conjugated polymer layer in phosphorescent organic light-emitting devices (OLEDs). Poly(3-hexylthiophene) (P3HT) nanolayers (thickness = ~1 nm thick), which were subjected to thermal annealing at 140 °C by varying annealing time, were inserted between indium tin oxide (ITO) anodes and hole transport layers (N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine, NPB). The 1 nm-thick P3HT layers showed very weak absorption in the visible light range of 500~650 nm. The device results disclosed that the presence of P3HT layers were just able to improve the charge injection of OLEDs leading to an enhanced luminance irrespective of thermal annealing condition. The highest luminance and efficiency were achieved for the OLEDs with the P3HT layers annealed at 140 °C for 10 min. Further annealing for 30 min resulted in turn-down of device performances. The emission color was almost unchanged by the presence of P3HT layers even though the color coordinates were marginally fluctuated according to the annealing time. The present result delivers the possibility to use p-type conjugated polymers (i.e., P3HT) as a hole injection layer in OLEDs.

Porosity Dependence of the Velocity of Surface and Bulk Acoustic Waves in Porous Silicon Carbide Films

2007 ◽  
Vol 556-557 ◽  
pp. 745-748 ◽  
Author(s):  
C.K. Young ◽  
G.T. Andrews ◽  
Maynard J. Clouter ◽  
Yue Ke ◽  
Wolfgang J. Choyke ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Porous Silicon ◽  
Acoustic Waves ◽  
Crystalline Silicon ◽  
Surface Acoustic Waves ◽  
Effective Medium ◽  
Bulk Acoustic Wave ◽  
Porous Silicon Carbide ◽  
Effective Medium Model ◽  
P Type

Brillouin light scattering spectroscopy was used to probe porous silicon carbide films formed from p-type 6H crystalline silicon carbide. The porosities of the films ranged from 30% to 58%. Surface and bulk acoustic wave velocities were measured and compared with those calculated from the Mori-Tanaka acoustic effective medium model. Qualitative agreement is obtained between the experimentally determined velocities and those predicted by Mori-Tanaka acoustic effective medium models with spherical pores and, in the case of surface acoustic waves, also with prolate spheroidal pores with shape factor equal to 0.2. The model demonstrates the importance of morphology in determining the behavior of acoustic waves in a porous material.

SURFACE ACOUSTIC WAVE INDUCED OPTICAL EFFECTS IN A NEMATIC LIQUID CRYSTAL

1993 ◽  
Vol 07 (17) ◽  
pp. 1167-1171
Author(s):  
A. K. GEORGE
Keyword(s):  
Liquid Crystal ◽  
Theoretical Model ◽  
Acoustic Wave ◽  
Nematic Liquid Crystal ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Crystal Film ◽  
Optical Effects ◽  
Wave Induced

The optical changes occurring in a homeotropically aligned nematic liquid crystal film when excited by surface acoustic waves have been studied. Striped domains at low acoustic intensities followed by acoustic streaming at high intensities have been observed. The increase in transparency of the oriented liquid crystal film under the action of surface acoustic waves also has been investigated. The experimental results compare favourably with the available theoretical model based on the effect of rotation of the plane of polarization.

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