Quantum Well Nanopillar Transistors

2006 ◽  
Vol 913 ◽  
Author(s):  
Shu-Fen Hu ◽  
Chin-Lung Sung
Keyword(s):  
Silicon Nitride ◽  
Quantum Well ◽  
Quantum Wells ◽  
High Speed ◽  
Load Resistance ◽  
Material System ◽  
Poly Silicon ◽  
Asymmetric Quantum ◽  
Small Load ◽  
Silicon Silicon

AbstractWe have fabricated vertical quantum well nanopillar transistors that consist of a vertical stack of coupled asymmetric quantum wells in a poly-silicon/ silicon nitride multilayer nano-pillars configuration with each well having a unique size. The devices consist of resonant tunneling in the poly-silicon/ silicon nitride stacked pillar material system surrounded by a Schottky gate. The gate electrode surrounds half side of a silicon pillar island, and the channel region exists at all the pillar silicon island. Current-voltage measurements at room temperature show prominent quantum effects due to electron resonance tunneling with side-gate. Accordingly, the vertical transistor offers high-shrinkage feature. By using the occupied area of the ULSI can be shrunk to 10% of that using conventional planar transistor. The small-occupied area leads to the small capacitance and the small load resistance, resulting in high speed and low power operation.

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.

Third-Harmonic Generation in Special Parabolic Quantum Wells

2013 ◽  
Vol 760-762 ◽  
pp. 392-396
Author(s):  
You Bin Yu
Keyword(s):  
Quantum Well ◽  
Density Matrix ◽  
Quantum Wells ◽  
Harmonic Generation ◽  
Third Harmonic Generation ◽  
Third Harmonic ◽  
The Third ◽  
Compact Density ◽  
Asymmetric Quantum ◽  
Parabolic Quantum Wells

Third-harmonic generation in a special asymmetric quantum well is investigated. The third-harmonic generation coefficient is carried out by applying compact-density-matrix method. The numerical results are presented for a GaAs/AlGaAs asymmetric quantum well. The very large third-harmonic generation coefficient is obtained in this quantum well. Moreover, the third-harmonic generation coefficient dependents on the quantum well parameters are investigated, respectively.

InGaAs/GaAsSb Heterostructures: Aluminum-Free Intersubband Devices

2009 ◽  
Vol 1195 ◽  
Author(s):  
Michele Nobile ◽  
Gottfried Strasser ◽  
Hermann Detz ◽  
Elvis Mujagic ◽  
Aaron Andrews ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Cascade Laser ◽  
Multiple Quantum Well ◽  
Wavelength Region ◽  
Threshold Current ◽  
Multiple Quantum ◽  
Material System ◽  
Quantum Cascade ◽  
Intersubband Absorption

AbstractAn experimental study on mid-infrared intersubband absorption in InGaAs/GaAsSb multiple quantum wells grown lattice-matched to InP substrates by molecular beam epitaxy is presented. Intersubband absorption in a broad wavelength region (5.8 - 11.6 μm) is observed in multiple quantum well samples with well widths ranging between 4.5 and 12 nm. A conduction band offset at the InGaAs/GaAsSb heterointerface of 360 meV gives an excellent agreement between the theoretically calculated ISB transition energies and the Fourier-transform infrared spectroscopy measurements over the whole range of well widths under investigation. Two kinds of intersubband devices based on the InGaAs/GaAsSb material system are presented: a quantum well infrared photodetector operating at a wavelength of 5.6μm and an aluminum-free quantum cascade laser. The presented quantum cascade laser emits at a wavelength of 11.3 μm, with a threshold current density of 1.7 kA/cm2 at 78 K.

The electronic states and the optical absorption for an asymmetrical quantum well applied with an external electric field

2019 ◽  
Vol 33 (26) ◽  
pp. 1950301 ◽  
Author(s):  
Yu Liu ◽  
Youbin Yu
Keyword(s):  
Optical Absorption ◽  
Iterative Method ◽  
Electric Field ◽  
Quantum Well ◽  
Quantum Wells ◽  
External Electric Field ◽  
Electronic States ◽  
Matrix Approach ◽  
Absorption Coefficients ◽  
Asymmetric Quantum

Electric field influences on the electronic states and the optical absorption in an asymmetrical quantum well with semiparabolic potential are investigated. The formula for the absorption coefficients in this asymmetrical quantum well with electric field are deduced by applying iterative method and density-matrix approach. The results are discussed with GaAs/AlGaAs materials and show that the external electric field has a significant effect on the electronic states and absorption coefficients of asymmetric quantum wells.

Research on the Electronic Tunneling in Asymmetric Dual-Quantum-Well

2012 ◽  
Vol 542-543 ◽  
pp. 953-958
Author(s):  
Xia Zheng Bu ◽  
Jian Wang ◽  
Ju Liang Shi ◽  
Hui Zhao
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Inductively Coupled Plasma ◽  
Energy Levels ◽  
Tunneling Effect ◽  
Material System ◽  
Inductively Coupled ◽  
Quantum Well Structure ◽  
Electronic Tunneling ◽  
Dual Quantum

An Al0.3Ga0.7As/GaAs/Al0.3Ga0.7As/GaAs/Al0.3Ga0.7As asymmetric dual-quantum-well structure was designed. The barrier thickness between the dual quantum wells is 48Å, it is thick enough to inhibit the mutual cross-interference between the energy levels within the two quantum wells. This material system was grown on a GaAs substrate by solid source molecular beam epitaxy, and the device was fabricated with rat electrodes using inductively coupled plasma etching mesa process. The tunneling effect that electron transfer through the dual-quantum-well structure was observed in the device I-V feature, it was calculated and demonstrated by transmission matrix method and Ariy Function numerical transform.

Second-Order Nonlinear Optical Effect in an Asymmetric Quantum Well

2013 ◽  
Vol 389 ◽  
pp. 1075-1079 ◽  
Author(s):  
You Bin Yu
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Nonlinear Optical ◽  
Second Order ◽  
Optical Effect ◽  
Nonlinear Optical Effect ◽  
Bulk Gaas ◽  
Optical Coefficient ◽  
Asymmetric Quantum ◽  
Nonlinear Optical Coefficient

The second-order nonlinear optical effect in asymmetric quantum wells is investigated. By using compact density-matrix approach, the analytical expression of the second-order nonlinear optical coefficient is obtained. The results show that the second-order nonlinear optical coefficient increases with the increasing of the asymmetry of quantum well. In addition, the nonlinear optical coefficient which obtained in this asymmetric quantum well is very larger than that obtained in bulk GaAs.

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