scholarly journals PL Spectra and Hot Charge Carrier Phenomena in an Undoped GaAs/AlGaAs Tunnel-Coupled Quantum Well

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Kanothai Jarusirirangsi ◽  
Paphavee van Dommelen ◽  
Chalongrat Daengngam
Keyword(s):  
Experimental Study ◽  
Quantum Well ◽  
Quantum Confinement ◽  
High Energy ◽  
Hot Electrons ◽  
Hot Electron ◽  
Energy Rate ◽  
Pl Spectra ◽  
Coupled Quantum Well ◽  
Undoped Gaas

In this research, we experimentally investigated the photoluminescence (PL) spectra of an undoped GaAs/Al0.36Ga0.64As Tunnel-Coupled Quantum Well (TCQW) at 300 K and 77 K. At 300 K, PL spectra were broadened at various laser intensities due to the characteristic quantum-confinement electron levels in the active region of the TCQW during pumping excitation. At 77 K, at selected excitation intensities, the high-energy tails in the PL spectra of the studied structure corresponded with hot electron temperatures as functions of the energy of emitted photons. The average scattering energy rate of hot electrons in the system was also studied at a lattice temperature of 77 K. The average scattering energy rate of hot electrons obtained from this experimental study was in agreement with the calculated theoretical value.

Determination of the Valence Band Offset in GaAs/(Ga,Al)As Superlattices by Hot Electron Excitation Spectroscopy

1993 ◽  
Vol 300 ◽  
Author(s):  
H. Weinert ◽  
A. Zukauskas ◽  
V. Latinis ◽  
V. Stepankevicius
Keyword(s):  
Electron Excitation ◽  
High Energy ◽  
Relaxation Processes ◽  
Hot Electron ◽  
X Ray Diffraction ◽  
Excitation Energies ◽  
Pl Spectra ◽  
Lower Excitation ◽  
Diffraction Barrier

ABSTRACTA GaAs/Ga1−xA1xAs-superlattice was investigated using quasi-cw PL measurements at T=2 K. The relevant sample parameters were determined by X-ray diffraction: barrier thickness - 5 nm, qw-thickness - 5 nm, x = 0.41. A series of PL-spectra at medium, but constant excitation intensity for different excitation energy (from 1.64 eV to 2.1 eV) was measured. From the high-energy slope of the PL-spectra the electron-temperature Te was determined. A clearly structured dependence of Te on hvexc (excitation energy) was found. We assumed the pronounced structures of the Te - hvexc - hvexc - “spectrum” to be the onset-energies of new, for lower excitation energies not possible relaxation processes. Calculating the excess energy for each kind of carriers (heavy and light holes and electrons) separately, we found δEv=( 0.18 ± 0.05) ∆Eg for the investigated sample. Using this new experimental method one also is able to obtain the energies of higher electronic states (for example Γ → L -transitions) of GaAs/(Ga,Al)Assuperlattices.

Detection of terahertz radiation by hot electron effects in coupled quantum well photodiodes

1996 ◽  
Vol 69 (23) ◽  
pp. 3569-3571 ◽  
Author(s):  
R. J. Stone ◽  
J. G. Michels ◽  
S. L. Wong ◽  
C. T. Foxon ◽  
R. J. Nicholas ◽  
...  
Keyword(s):  
Quantum Well ◽  
Terahertz Radiation ◽  
Hot Electron ◽  
Coupled Quantum Well ◽  
Electron Effects

scholarly journals Plasmonic hot-electron photodetection with quasi-bound states in the continuum and guided resonances

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenhao Wang ◽  
Lucas V. Besteiro ◽  
Peng Yu ◽  
Feng Lin ◽  
Alexander O. Govorov ◽  
...  
Keyword(s):  
Bound States ◽  
Structural Parameters ◽  
Hybrid Structure ◽  
Fine Tuning ◽  
Hot Electrons ◽  
Hot Electron ◽  
Perfect Absorption ◽  
High Loss ◽  
Guided Mode ◽  
The Continuum

Abstract Hot electrons generated in metallic nanostructures have shown promising perspectives for photodetection. This has prompted efforts to enhance the absorption of photons by metals. However, most strategies require fine-tuning of the geometric parameters to achieve perfect absorption, accompanied by the demanding fabrications. Here, we theoretically propose a Ag grating/TiO2 cladding hybrid structure for hot electron photodetection (HEPD) by combining quasi-bound states in the continuum (BIC) and plasmonic hot electrons. Enabled by quasi-BIC, perfect absorption can be readily achieved and it is robust against the change of several structural parameters due to the topological nature of BIC. Also, we show that the guided mode can be folded into the light cone by introducing a disturbance to become a guided resonance, which then gives rise to a narrow-band HEPD that is difficult to be achieved in the high loss gold plasmonics. Combining the quasi-BIC and the guided resonance, we also realize a multiband HEPD with near-perfect absorption. Our work suggests new routes to enhance the light-harvesting in plasmonic nanosystems.

scholarly journals Asymmetric Ge/SiGe coupled quantum well modulators

Nanophotonics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1765-1773
Author(s):  
Yi Zhang ◽  
Jianfeng Gao ◽  
Senbiao Qin ◽  
Ming Cheng ◽  
Kang Wang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Quantum Well ◽  
Quantum Wells ◽  
High Speed ◽  
Low Voltage ◽  
Extinction Ratio ◽  
High Frequency Response ◽  
Modulation Format ◽  
Silicon Photonic ◽  
Coupled Quantum Well

Abstract We design and demonstrate an asymmetric Ge/SiGe coupled quantum well (CQW) waveguide modulator for both intensity and phase modulation with a low bias voltage in silicon photonic integration. The asymmetric CQWs consisting of two quantum wells with different widths are employed as the active region to enhance the electro-optical characteristics of the device by controlling the coupling of the wave functions. The fabricated device can realize 5 dB extinction ratio at 1446 nm and 1.4 × 10−3 electrorefractive index variation at 1530 nm with the associated modulation efficiency V π L π of 0.055 V cm under 1 V reverse bias. The 3 dB bandwidth for high frequency response is 27 GHz under 1 V bias and the energy consumption per bit is less than 100 fJ/bit. The proposed device offers a pathway towards a low voltage, low energy consumption, high speed and compact modulator for silicon photonic integrated devices, as well as opens possibilities for achieving advanced modulation format in a more compact and simple frame.

Deep Levels Induced by High Fluence Proton Irradiation in Undoped GaAs Diodes

1997 ◽  
Vol 487 ◽  
Author(s):  
A Castaldini ◽  
A Cavallini ◽  
L Polenta ◽  
C Canali ◽  
F Nava ◽  
...  
Keyword(s):  
Proton Irradiation ◽  
High Energy ◽  
Deep Levels ◽  
Induced Current ◽  
High Fluence ◽  
High Fluences ◽  
Electron Beam Induced Current ◽  
Insulating Liquid ◽  
Undoped Gaas ◽  
Scanning Electron

AbstractSemi-insulating liquid encapsulated Czochralski grown GaAs has been investigated after irradiation at high fluences of high-energy protons. Electron beam induced current observations of scanning electron microscopy evidenced a radiation stimulated ordering. An analysis has been carried out of the deep levels associated with defects as a function of the irradiation fluence, using complementary current transient spectroscopies. By increasing the irradiation fluence, the concentration of the native traps at 0.37 eV together with that of the EL2 defect significantly increases and, at the same time, two new electron traps at 0.15 eV and 0.18 eV arise and quickly increase in density.

Quantum Confinement-Controlled Exchange Coupling in Manganese(II)-Doped CdSe Two-Dimensional Quantum Well Nanoribbons

Nano Letters ◽  
2012 ◽  
Vol 12 (10) ◽  
pp. 5311-5317 ◽  
Author(s):  
Rachel Fainblat ◽  
Julia Frohleiks ◽  
Franziska Muckel ◽  
Jung Ho Yu ◽  
Jiwoong Yang ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Confinement ◽  
Exchange Coupling ◽  
Two Dimensional
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