scholarly journals Configuration space method for calculating binding energies of exciton complexes in quasi-1D/2D semiconductors

2016 ◽  
Vol 30 (24) ◽  
pp. 1630006 ◽  
Author(s):  
I. V. Bondarev
Keyword(s):  
Binding Energy ◽  
Quantum Wells ◽  
Configuration Space ◽  
Binding Energies ◽  
Electron Hole ◽  
Coupled Quantum Wells ◽  
2D Semiconductors ◽  
Crossover Behavior ◽  
Confined Structures ◽  
Space Method

A configuration space method is developed for binding energy calculations of the lowest energy exciton complexes (trion, biexciton) in spatially confined quasi-1D semiconductor nanostructures such as nanowires and nanotubes. Quite generally, trions are shown to have greater binding energy in strongly confined structures with small reduced electron–hole masses. Biexcitons have greater binding energy in less confined structures with large reduced electron–hole masses. This results in a universal crossover behavior, whereby trions become less stable than biexcitons as the transverse size of the quasi-1D nanostructure increases. The method is also capable of evaluating binding energies for electron–hole complexes in quasi-2D semiconductors such as coupled quantum wells and bilayer van der Walls bound heterostructures with advanced optoelectronic properties.

The Effects on Electric Field and Hydrostatic Pressure on the Doped Properties in a Strained (In,Ga)N-GaN Coupled Quantum Wells

2021 ◽  
Vol 16 (1) ◽  
pp. 97-103
Author(s):  
Xin-Nan Li ◽  
Guang-Xin Wang ◽  
Xiu-Zhi Duan
Keyword(s):  
Hydrostatic Pressure ◽  
Binding Energy ◽  
Electric Field ◽  
Quantum Wells ◽  
Variational Approach ◽  
Coupled Quantum Wells ◽  
Zinc Blende ◽  
Impurity Interaction ◽  
The Right ◽  
Peak Value

A variational approach is utilized to investigated the electron-impurity interaction in zinc-blende (In,Ga)N-GaN strained coupled quantum wells. The donor imputrity states are studied in consideration of the effects of hydrostatic pressure and external electric field. Our results indicate that the binding energy visibly depends on hydrostatic pressure, strain of coupled quantum wells, and applied electric field. The binding energy demonstrates a peak value with the reduction of the left-well width, and which displays a minimum value with the increment of the middle-barrier width. A decreasing behavior on the binding energy is also demonstrated when the right-well width enhances. Also the binding energy augments constantly with the increasing hydrostatic pressure. Besides, the dependency of the binding energy on variation of impurity position has been analyzed detailedly.

NOVEL ELECTRON GAS SYSTEMS

1999 ◽  
Vol 13 (05n06) ◽  
pp. 479-488 ◽  
Author(s):  
GAETANO SENATORE ◽  
F. RAPISARDA ◽  
S. CONTI
Keyword(s):  
Phase Diagram ◽  
Quantum Wells ◽  
Recent Progress ◽  
Electron Gas ◽  
Total Charge ◽  
Diffusion Monte Carlo ◽  
Electron Hole ◽  
Coupled Quantum Wells ◽  
Hartree Fock ◽  
The Ideal

We review recent progress on the physics of electrons in the bilayered electron gas, relevant to coupled quantum wells in GaAs/AlGaAs heterostructures. First, we focus on the phase diagram of a symmetric bilayer at T=B=0, obtained by diffusion Monte Carlo simulations. It is found that inter–layer correlations stabilize crystalline structures at intermediate inter–layer separation, while favouring a liquid phase at smaller distance. Also, the available DMC evidence is in contrast with the recently (Hartree–Fock) predicted total charge transfer (TCT), whereby all the electron spontaneously jump in one layer. In fact, one can show that such a TCT state is never stable in the ideal bilayer with no tunneling. We finally comment on ongoing DMC investigations on the electron-hole bilayer, where excitonic condensation is expected to take place.

scholarly journals Giant gate-tunable bandgap renormalization and excitonic effects in a 2D semiconductor

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw2347 ◽  
Author(s):  
Zhizhan Qiu ◽  
Maxim Trushin ◽  
Hanyan Fang ◽  
Ivan Verzhbitskiy ◽  
Shiyuan Gao ◽  
...  
Keyword(s):  
Binding Energy ◽  
Single Layer ◽  
Scanning Tunneling Spectroscopy ◽  
Binding Energies ◽  
Exciton Binding Energy ◽  
Scanning Tunneling ◽  
Full Potential ◽  
2D Semiconductors ◽  
Wide Range ◽  
Excitonic Effects

Understanding the remarkable excitonic effects and controlling the exciton binding energies in two-dimensional (2D) semiconductors are crucial in unlocking their full potential for use in future photonic and optoelectronic devices. Here, we demonstrate large excitonic effects and gate-tunable exciton binding energies in single-layer rhenium diselenide (ReSe2) on a back-gated graphene device. We used scanning tunneling spectroscopy and differential reflectance spectroscopy to measure the quasiparticle electronic and optical bandgap of single-layer ReSe2, respectively, yielding a large exciton binding energy of 520 meV. Further, we achieved continuous tuning of the electronic bandgap and exciton binding energy of monolayer ReSe2 by hundreds of milli–electron volts through electrostatic gating, attributed to tunable Coulomb interactions arising from the gate-controlled free carriers in graphene. Our findings open a new avenue for controlling the bandgap renormalization and exciton binding energies in 2D semiconductors for a wide range of technological applications.

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