An Intrinsic Model for Radiative Recombination in Porous Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
Mark S. Hybertsen
Keyword(s):  
Matrix Element ◽  
Porous Silicon ◽  
Radiative Recombination ◽  
Energy Shift ◽  
Short Length ◽  
Length Scale ◽  
Dipole Matrix Element ◽  
Light Emitting ◽  
Recombination Time

A microcrystalline model for the light emitting portion of porous silicon is outlined. Confinement to a short length scale induces an effective direct dipole matrix element for radiative recombination. The radiative recombination time is strongly size (hence confinement induced energy shift) dependent, and in the microsecond regime for blue shifts of ˜1 eV. Trends and comparison to experiment are discussed.

Theory of the Physical Properties of Si Nanocrystals

1994 ◽  
Vol 358 ◽  
Author(s):  
M. Lannoo ◽  
C. Delerue ◽  
G. Allan ◽  
E. Martin
Keyword(s):  
Porous Silicon ◽  
Radiative Recombination ◽  
Surface Defects ◽  
Stokes Shift ◽  
Optical Excitation ◽  
Recombination Time ◽  
Si Nanocrystals ◽  
Donor And Acceptor ◽  
Electron Hole Pair ◽  
Level Of Understanding

ABSTRACTThis paper reviews calculations concerning several aspects of silicon crystallites and their relevance for porous silicon. This begins with the optical properties of perfect crystallites: gap versus size, radiative recombination time, relative importance of phonon assisted transitions. A second part is devoted to the determination of the excitonic exchange splitting and of the Stokes shift which are found to bring a similar contribution (∼10 to 20 meV). The effect of surface defects like dangling bonds is then investigated with their contribution to the recombination time. The Auger non radiative recombination time is also calculated and found to be short (∼1 nsec). This is confirmed by some experiments on porous silicon which show a saturation effect of the photoluminescence under intense optical excitation or under cathodic polarization in aqueous solution, Auger recombination preventing the existence of more than one electron-hole pair per crystallite. Donor and acceptor impurities are studied in detail (screening of Coulomb potential, notion of ionization energy) with the conclusion that they are ionized. A final discussion shows the present level of understanding and identifies problems remaining to be solved.

n-type GaN surface etched green light-emitting diode to reduce non-radiative recombination centers

2021 ◽  
Vol 118 (2) ◽  
pp. 021102
Author(s):  
Dong-Pyo Han ◽  
Ryoto Fujiki ◽  
Ryo Takahashi ◽  
Yusuke Ueshima ◽  
Shintaro Ueda ◽  
...  
Keyword(s):  
Radiative Recombination ◽  
Light Emitting Diode ◽  
Green Light ◽  
Light Emitting ◽  
Recombination Centers

New Results on Electroluminescence from Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
Peter Steiner ◽  
Frank Kozlowski ◽  
Hermann Sandmaier ◽  
Walter Lang
Keyword(s):  
Porous Silicon ◽  
Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Uv Light ◽  
Green Light ◽  
Light Emitting ◽  
Porous Region ◽  
First Results

ABSTRACTFirst results on light emitting diodes in porous silicon were reported in 1991. They showed a quantum efficiency of 10-7 to 10-5 and an orange spectrum. Over the last year some progress was achieved:- By applying UV-light during the etching blue and green light emitting diodes in porous silicon are fabricated.- When a p/n junction is realized within the porous region, a quantum efficiency of 10-4 is obtained.

Impact of Anchoring Monolayers on the Enhancement of Radiative Recombination in Light-Emitting Diodes Based on Silicon Nanocrystals

2018 ◽  
Vol 122 (11) ◽  
pp. 6422-6430 ◽  
Author(s):  
Batu Ghosh ◽  
Takumi Hamaoka ◽  
Yoshihiro Nemoto ◽  
Masaki Takeguchi ◽  
Naoto Shirahata
Keyword(s):  
Silicon Nanocrystals ◽  
Radiative Recombination ◽  
Light Emitting Diodes ◽  
Light Emitting

LUMINESCENCE BEHAVIOR AND MECHANISM OF LIGHT-EMITTING POROUS SILICON

1994 ◽  
Vol 08 (02) ◽  
pp. 69-92 ◽  
Author(s):  
XUN WANG
Keyword(s):  
Porous Silicon ◽  
Blue Light ◽  
Light Emission ◽  
Energy State ◽  
Surface Recombination Velocity ◽  
Luminescence Spectroscopy ◽  
Carrier Injection ◽  
Blue Light Emission ◽  
Light Emitting ◽  
Si Nanostructures

In this review article, we give a new insight into the luminescence mechanism of porous silicon. First, we observed a “pinning” characteristic of photoluminescent peaks for as-etched porous silicon samples. It was explained as resulting from the discontinuous variation of the size of Si nanostructures, i.e. the size quantization. A tight-binding calculation of the energy band gap widening versus the dimension of nanoscale Si based on the closed-shell Si cluster model agrees well with the experimental observations. Second, the blue-light emission from porous silicon was achieved by using boiling water treatment. By investigating the luminescence micrographic images and the decaying behaviors of PL spectra, it has been shown that the blue-light emission is believed to be originated from the porous silicon skeleton rather than the surface contaminations. The conditions for achieving blue light need proper size of Si nanostructures, low-surface recombination velocity, and mechanically strong skeleton. The fulfillment of these conditions simultaneously is possible but rather critical. Third, the exciton dynamics in light-emitting porous silicon is studied by using the temperature-dependent and picosecond time-resolved luminescence spectroscopy. A direct evidence of the existence of confined excitons induced by the quantum size effect has been revealed. Two excitation states are found to be responsible for the visible light emission, i.e. a higher lying energy state corresponding to the confined excitons in Si nanostructures and a lower lying state related with surfaces of Si wires or dots. A picture of the carrier transfer between the quantum confined state and the surface localized state has been proposed. Finally, we investigated the transient electroluminescence behaviors of Au/porous silicon/Si/Al structure and found it is very similar to that of an ordinary p-n junction light-emitting diode. The mechanism of electroluminescence is explained as the carrier injection through the Au/porous silicon Schotky barrier and the porous silicon/p-Si heterojunction into the corrugated Si wires, where the radiative recombination of carriers occurs.

Porous silicon light-emitting diodes – mechanisms in the operation

2001 ◽  
Vol 17 (1-2) ◽  
pp. 111-116 ◽  
Author(s):  
K. Molnár ◽  
T. Mohácsy ◽  
M. Ádám ◽  
I. Bársony
Keyword(s):  
Porous Silicon ◽  
Light Emitting Diodes ◽  
Light Emitting

Light emitting porous silicon diode based on a silicon/porous silicon heterojunction

1999 ◽  
Vol 86 (11) ◽  
pp. 6474-6482 ◽  
Author(s):  
L. Pavesi ◽  
R. Chierchia ◽  
P. Bellutti ◽  
A. Lui ◽  
F. Fuso ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Light Emitting ◽  
Silicon Diode
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