The Red Light Emission in 2D (C4SH3CH2NH3)2SnI4 and (C4OH7CH2NH3)2SnI4 Perovskites

2021 ◽  
Author(s):  
Mi Hee Jung

Two dimensional (2D) perovskites have a large exciton binding energy due to the structure of the quantum confinement, which produces a faster radiative recombination, so it is a promising potential...

MRS Bulletin ◽  
1998 ◽  
Vol 23 (4) ◽  
pp. 33-38 ◽  
Author(s):  
Leonid Tsybeskov

Light emission in silicon has been intensively investigated since the 1950s when crystalline silicon (c-Si) was recognized as the dominant material in microelectronics. Silicon is an indirect-bandgap semiconductor and momentum conservation requires phonon assistance in radiative electron-hole recombination (Figure 1a, top left). Because phonons carry a momentum and an energy, the typical signature of phonon-assisted recombination is several peaks in the photoluminescence (PL) spectra at low temperature. These PL peaks are called “phonon replicas.” High-purity c-Si PL is caused by free-exciton self-annihilation with the exciton binding energy of ~11 meV. The TO-phonon contribution in conservation processes is most significant, and the main PL peak (~1.1 eV) is shifted from the bandgap value (~1.17 eV) by ~70 meV—that is, the exciton binding energy plus TO-phonon energy (Figure 1a).


Nanophotonics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 2017-2032 ◽  
Author(s):  
Chitraleema Chakraborty ◽  
Nick Vamivakas ◽  
Dirk Englund

AbstractTwo-dimensional (2D) materials are being actively researched due to their exotic electronic and optical properties, including a layer-dependent bandgap, a strong exciton binding energy, and a direct optical access to electron valley index in momentum space. Recently, it was discovered that 2D materials with bandgaps could host quantum emitters with exceptional brightness, spectral tunability, and, in some cases, also spin properties. This review considers the recent progress in the experimental and theoretical understanding of these localized defect-like emitters in a variety of 2D materials as well as the future advantages and challenges on the path toward practical applications.


2020 ◽  
Vol 13 (6) ◽  
Author(s):  
S. Ahmad ◽  
M. Zubair ◽  
O. Jalil ◽  
M. Q. Mehmood ◽  
U. Younis ◽  
...  

1990 ◽  
Vol 04 (15n16) ◽  
pp. 2345-2356
Author(s):  
Y. FU ◽  
K. A. CHAO

Exciton binding energy in semiconductor multiple quantum well (MQW) systems is analyzed with both the variational method and the perturbation theory. The intrinsic deficiency of the use of the two-dimensional exciton envelop wave function is clearly demonstrated. Using a GaAs/Al x Ga 1−xAs MQW as an example to calculate the exciton binding energy with a variational three-dimensional trial envelop function, we found that in many realistic samples the spatial extension of an exciton covers a region of several lattice constant dA + dB, where dA is the barrier width and dB is the well width.


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