Room Temperature Band-Edge Luminescence from Silicon Grains Prepared by the Recrystallization of Mesoporous Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
Karen L. Moore ◽  
Leonid Tsybeskov ◽  
Philippe M. Fauchet ◽  
Dennis G. Hall
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Band Edge ◽  
Applied Bias ◽  
Mesoporous Silicon ◽  
Room Temperature Photoluminescence ◽  
Band Edge Luminescence ◽  
A Current ◽  
Better Than

AbstractRoom-temperature photoluminescence (PL) peaking at 1.1 eV has been found in electrochemically etched mesoporous silicon annealed at 950°C. Low-temperature PL spectra clearly show a fine structure related to phonon-assisted transitions in pure crystalline silicon (c-Si) and the absence of defect-related (e.g.P-line) and impurity-related (e.g.oxygen, boron) transitions. The maximum PL external quantum efficiency (EQE) is found to be better than 0.1% with a weak temperature dependence in the region from 12K to 400K. The PL intensity is a linear function of excitation intensity up to 100 W/cm2. The PL can be suppressed by an external electric field ≥ 105 V/cm. Room temperature electroluminescence (EL) related to the c-Si band-edge is also demonstrated under an applied bias ≤ 1.2 V and with a current density ≈ 20 mA/cm2. A model is proposed in which the radiative recombination originates from recrystallized Si grains within a non-stoichiometric Si-rich silicon oxide (SRSO) matrix.

Light Emission from Intrinsic and Doped Silicon-Rich Silicon Oxide: from the Visible to 1.6 ΜM

1996 ◽  
Vol 452 ◽  
Author(s):  
L. Tsybeskov ◽  
K. L. Moore ◽  
P. M. Fauchet ◽  
D. G. Hall
Keyword(s):  
Rare Earth ◽  
External Quantum Efficiency ◽  
Room Temperature ◽  
Structural Modification ◽  
Silicon Oxide ◽  
Light Emission ◽  
Crystalline Silicon ◽  
Light Emitting ◽  
Infra Red ◽  
Doped Silicon

AbstractSilicon-rich silicon oxide (SRSO) films were prepared by thermal oxidation (700°C-950°C) of electrochemically etched crystalline silicon (c-Si). The annealing-oxidation conditions are responsible for the chemical and structural modification of SRSO as well as for the intrinsic light-emission in the visible and near infra-red spectral regions (2.0–1.8 eV, 1.6 eV and 1.1 eV). The extrinsic photoluminescence (PL) is produced by doping (via electroplating or ion implantation) with rare-earth (R-E) ions (Nd at 1.06 μm, Er at 1.5 μm) and chalcogens (S at ∼1.6 μm). The impurities can be localized within the Si grains (S), in the SiO matrix (Nd, Er) or at the Si-SiO interface (Er). The Er-related PL in SRSO was studied in detail: the maximum PL external quantum efficiency (EQE) of 0.01–0.1% was found in samples annealed at 900°C in diluted oxygen (∼ 10% in N2). The integrated PL temperature dependence is weak from 12K to 300K. Light emitting diodes (LEDs) with an active layer made of an intrinsic and doped SRSO are manufactured and studied: room temperature electroluminescence (EL) from the visible to 1.6 μmhas been demonstrated.

Luminescence in Si/Strained Si1−xGex Heterostructures

1995 ◽  
Vol 379 ◽  
Author(s):  
J.C. Sturm ◽  
A. St. Amour ◽  
Y. Lacroix ◽  
M.L.W. Thewalt
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Surface Passivation ◽  
Band Edge ◽  
Strained Si ◽  
Edge Luminescence ◽  
Recent Developments ◽  
High Pump ◽  
Band Edge Luminescence ◽  
First Time

ABSTRACTThis paper quickly reviews the structure of band-edge luminescence in Si/strained Si1−xGex heterostructures, and then focusses on two recent developments -- the origin of “deep” sub-bandgap luminescence which is sometimes observed in structures grown by Molecular Beam Epitaxy (MBE) and the understanding of the temperature dependence of the band-edge luminescence (up to room temperature). Strong evidence will be presented that the origin of the deep luminescence is radiation damage, and that generated defects are segregated or trapped in the SilxGex layers. The modelling of the temperature dependence by twocarrier numerical simulation is presented for the first time. The work and experimental data show convincingly that the strength of the luminescence at high temperature is controlled by recombination at the top silicon surface, which in turn can be controlled by surface passivation. At high pump powers and low temperatures, Auger recombination reduces the lifetime in the Si1−xGex layers, and leads to a luminescence vs. temperature which is flat up to 250 K and which is reduced only by a factor of three at room temperature.

scholarly journals Effect of Photoconductivity of Silicon Oxide Passivation Film on the Performance of Crystalline Silicon Cell and Module

2021 ◽  
Vol 898 (1) ◽  
pp. 012010
Author(s):  
Shaoliang Wang ◽  
Gang Zhou ◽  
Yilun Wang ◽  
Xiaofan Deng ◽  
Bingxin Xie
Keyword(s):  
Film Thickness ◽  
Thermal Oxidation ◽  
Room Temperature ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Deposition Process ◽  
Good Stability ◽  
Ozone Oxidation ◽  
Passivation Film ◽  
Silicon Cell

Abstract In the paper, the effect of different deposition process of silicon oxide passivation film on the performance of crystalline silicon cell and module was studied. It was found that the thermal oxidation passivation film has better passivation effect than ozone oxidation passivation film at room temperature, and the cell and module has good stability and low attenuation. The thermal oxidation passivation effect is related to the film thickness. The thicker the film thickness is, the better the anti-PID (potential induced attenuation) performance is. The results can provide reference for photovoltaic industry.

Effects of N2O Fluence on the PECVD-grown Si-rich SiOx with Buried Si Nanocrystals

2005 ◽  
Vol 862 ◽  
Author(s):  
Chun-Jung Lin ◽  
Hao-Chung Kuo ◽  
Chia-Yang Chen ◽  
Yu-Lun Chueh ◽  
Li-Jen Chou ◽  
...  
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Chemical Vapor ◽  
Blue Shift ◽  
Annealing Process ◽  
Room Temperature Photoluminescence ◽  
Transmission Electron ◽  
Si Nanocrystals ◽  
20 Nm ◽  
Oxidation Effect

AbstractThe optimized N2O fluence is demonstrated for plasma enhanced chemical vapor deposition (PECVD) of Si-rich substoichiometric silicon oxide (SiOx) films with buried Si nanocrystals. Strong room-temperature photoluminescence (PL) at 550-870 nm has been observed in SiOx films grown by PECVD under a constant SiH4 fluence of 20 sccm with an N2O fluence varying from 105 sccm to 130 sccm. A 22-nm-redshift in the central PL wavelength has been detected after annealing from 15 min to 180 min. The maximum PL irradiance is observed from the SiOx film grown at the optimal N2O fluence of 120 sccm after annealing for 30 minutes. Larger N2O fluence or longer annealing time leads to a PL band that is blue-shifted by 65 nm and 20 nm, respectively. Such a blue shift is attributed to shrinkage in the size of the Si nanocrystals with the participation of oxygen atoms from N2O incorporated within the SiOx matrix. The (220)-oriented Si nanocrystals exhibit radii ranging from 4.4 nm to 5.0 nm as determined by transmission electron microscopy (TEM). The luminescent lifetime lengthens to 52 μs as the nc-Si size increase to > 4 nm. Optimal annealing times for SiOx films prepared at different N2O fluences are also reported. A longer annealing process results in a stronger oxidation effect in SiOx films prepared at higher N2O fluences, yielding a lower PL irradiance at shorter wavelengths. In contrast, larger Si nanocrystals can be precipitated when the N2O fluence becomes lower; however, such a SiOx film usually exhibits weaker PL at longer wavelength due to a lower nc-Si density. These results indicate that a N2O/SiH4 fluence ratio of 6:1 is the optimized PECVD growth condition for the Si-rich SiO2 wherein dense Si nanocrystals are obtained after annealing.

Multiwafer Movpe of III-Nitride Films for Led and Laser Applications

1997 ◽  
Vol 482 ◽  
Author(s):  
R. Beccard ◽  
O. Schoen ◽  
B. Schineller ◽  
D. Schmitz ◽  
M. Heuken ◽  
...  
Keyword(s):  
Room Temperature ◽  
State Of The Art ◽  
Low Cost ◽  
Free Exciton ◽  
Single Layer ◽  
Laser Applications ◽  
Room Temperature Photoluminescence ◽  
Cost Of Ownership ◽  
P Type ◽  
Better Than

AbstractProcess for mass production of GaN and its related alloys, InGaN and AlGaN, have been optimized to achieve high device yield and low cost of ownership. Here we present some of the latest results obtained from AIX 2000 HT Planetary Reactor® in a configuration of 7×2” which provides unique uniformity capabilities due to the two fold rotation of the substrates. GaiN single layers with background electron concentrations below 5·1016 cm-3 and intended doping levels up to 1018 cm-3 p-type and 1020 cm-3 n-type with state of the art homogeneities have been achieved. Thickness homogeneities have been shown to be better than 1% standard deviation on full 2” wafers, while composition uniformity of ternary material is determined by room temperature photoluminescence mappings. Low temperature photoluminescence and reflectance spectra of single layer GaN revealed free exciton transitions.

Room-temperature photoluminescence and electroluminescence from Er-doped silicon-rich silicon oxide

1997 ◽  
Vol 70 (14) ◽  
pp. 1790-1792 ◽  
Author(s):  
L. Tsybeskov ◽  
S. P. Duttagupta ◽  
K. D. Hirschman ◽  
P. M. Fauchet ◽  
K. L. Moore ◽  
...  
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Room Temperature Photoluminescence ◽  
Doped Silicon ◽  
Er Doped
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