scholarly journals Band alignment in quantum wells from automatically tuned DFT+U

2019 ◽  
Vol 21 (11) ◽  
pp. 5966-5973 ◽  
Author(s):  
Grigory Kolesov ◽  
Chungwei Lin ◽  
Andrew Knyazev ◽  
Keisuke Kojima ◽  
Joseph Katz ◽  
...  

Accurate band offsets in III–V zinc blende-alloy quantum wells were obtained computationally with the DFT+U method automatically tuned to reproduce bulk properties.

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Ya-Wei Huan ◽  
Ke Xu ◽  
Wen-Jun Liu ◽  
Hao Zhang ◽  
Dmitriy Anatolyevich Golosov ◽  
...  

AbstractHybrid heterojunctions based on two-dimensional (2D) and conventional three-dimensional (3D) materials provide a promising way toward nanoelectronic devices with engineered features. In this work, we investigated the band alignment of a mixed-dimensional heterojunction composed of transferred MoS2 on β-Ga2O3($$ 2- $$2-01) with and without nitridation. The conduction and valence band offsets for unnitrided 2D-MoS2/3D-β-Ga2O3 heterojunction were determined to be respectively 0.43 ± 0.1 and 2.87 ± 0.1 eV. For the nitrided heterojunction, the conduction and valence band offsets were deduced to 0.68 ± 0.1 and 2.62 ± 0.1 eV, respectively. The modified band alignment could result from the dipole formed by charge transfer across the heterojunction interface. The effect of nitridation on the band alignments between group III oxides and transition metal dichalcogenides will supply feasible technical routes for designing their heterojunction-based electronic and optoelectronic devices.


1991 ◽  
Vol 240 ◽  
Author(s):  
Emil S. Koteies

ABSTRACTWe have developed a novel experimental technique for accurately determining band offsets in semiconductor quantum wells (QW). It is based on the fact that the ground state heavy- hole (HH) band energy is more sensitive to the depth of the valence band well than the light-hole (LH) band energy. Further, it is well known that as a function of the well width, Lz, the energy difference between the LH and HH excitons in a lattice matched, unstrained QW system experiences a maximum. Calculations show that the position, and more importantly, the magnitude of this maximum is a sensitive function of the valence band offset, Qy, which determines the depth of the valence band well. By fitting experimentally measured LH-HH splittings as a function of Lz, an accurate determination of band offsets can be derived. We further reduce the experimental uncertainty by plotting LH-HH as a function of HH energy (which is a function of Lz ) rather than Lz itself, since then all of the relevant parameters can be precisely determined from absorption spectroscopy alone. Using this technique, we have derived the conduction band offsets for several material systems and, where a consensus has developed, have obtained values in good agreement with other determinations.


2015 ◽  
Vol 252 (4) ◽  
pp. 670-677 ◽  
Author(s):  
C. M. Duque ◽  
A. L. Morales ◽  
M. E. Mora-Ramos ◽  
C. A. Duque

2007 ◽  
Vol 515 (10) ◽  
pp. 4488-4491 ◽  
Author(s):  
Dipankar Biswas ◽  
Subindu Kumar ◽  
Tapas Das
Keyword(s):  

1997 ◽  
Vol 79 (2) ◽  
pp. 269-272 ◽  
Author(s):  
M. L. W. Thewalt ◽  
D. A. Harrison ◽  
C. F. Reinhart ◽  
J. A. Wolk ◽  
H. Lafontaine

2010 ◽  
Vol 42 (8) ◽  
pp. 2131-2133 ◽  
Author(s):  
Sanjib Kabi ◽  
Tapas Das ◽  
Dipankar Biswas
Keyword(s):  

1991 ◽  
Vol 30 (Part 2, No. 9B) ◽  
pp. L1631-L1634 ◽  
Author(s):  
Xiong Zhang ◽  
Kentaro Onabe ◽  
Yoshiki Nitta ◽  
Baoping Zhang ◽  
Susumu Fukatsu ◽  
...  

2021 ◽  
Vol 16 (1) ◽  
pp. 97-103
Author(s):  
Xin-Nan Li ◽  
Guang-Xin Wang ◽  
Xiu-Zhi Duan

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.


Author(s):  
Vurgaftman Igor

This chapter shows how to calculate the absorption coefficient, optical gain, and radiative recombination rates in quantum wells and superlattices. A detailed treatment of both interband and intersubband transitions is presented, and their differences and similarities are considered in detail. The optical properties of wurtzite quantum wells and zinc-blende quantum wires and dots are also discussed. Finally, the interaction of excitonic transitions with incident light in quantum wells is considered as a model for other two-dimensional materials.


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