Optical characterization of excess carrier lifetime and surface recombination in 4H/6H–SiC

2001 ◽  
Vol 79 (3) ◽  
pp. 365-367 ◽  
Author(s):  
A. Galeckas ◽  
J. Linnros ◽  
M. Frischholz ◽  
V. Grivickas
Keyword(s):  
Carrier Lifetime ◽  
Surface Recombination ◽  
Optical Characterization ◽  
Excess Carrier

scholarly journals Surface passivation and optical characterization of Al2O3/a-SiCx stacks on c-Si substrates

2013 ◽  
Vol 4 ◽  
pp. 726-731 ◽  
Author(s):  
Gema López ◽  
Pablo R Ortega ◽  
Cristóbal Voz ◽  
Isidro Martín ◽  
Mónica Colina ◽  
...  
Keyword(s):  
Wavelength Range ◽  
Surface Passivation ◽  
Crystalline Silicon ◽  
Surface Recombination ◽  
Chemical Vapor ◽  
Optical Characterization ◽  
Surface Recombination Velocity ◽  
Carrier Injection ◽  
Si Substrates

The aim of this work is to study the surface passivation of aluminum oxide/amorphous silicon carbide (Al2O3/a-SiCx) stacks on both p-type and n-type crystalline silicon (c-Si) substrates as well as the optical characterization of these stacks. Al2O3 films of different thicknesses were deposited by thermal atomic layer deposition (ALD) at 200 °C and were complemented with a layer of a-SiCx deposited by plasma-enhanced chemical vapor deposition (PECVD) to form anti-reflection coating (ARC) stacks with a total thickness of 75 nm. A comparative study has been carried out on polished and randomly textured wafers. We have experimentally determined the optimum thickness of the stack for photovoltaic applications by minimizing the reflection losses over a wide wavelength range (300–1200 nm) without compromising the outstanding passivation properties of the Al2O3 films. The upper limit of the surface recombination velocity (S eff,max) was evaluated at a carrier injection level corresponding to 1-sun illumination, which led to values below 10 cm/s. Reflectance values below 2% were measured on textured samples over the wavelength range of 450–1000 nm.

Optical Characterization of Buried Ingaas/GaAs Wires Overgrown by MBE

1993 ◽  
Vol 318 ◽  
Author(s):  
K. Pieger ◽  
J. Straka ◽  
Ch. Gréus ◽  
A. Forchel
Keyword(s):  
Surface Recombination ◽  
Optical Characterization ◽  
Gaas Layer ◽  
Photoluminescence Intensity ◽  
Temperature Growth ◽  
Resolution Electron ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Induced Defects

ABSTRACTWe have prepared buried InGaAs/GaAs wires by high resolution electron beam lithography, wet chemical etching and subsequent MBE overgrowth. Wires with lateral widths of less than 40nm have been realized.For optimized regrowth conditions such as growth temperature, growth rate, III/V ratio, and arsenic flux a smooth surface morphology of the 100nm thick overgrown (Al)GaAs layer is obtained.Etched only ultra narrow wires show a decrease of radiative recombination due to process induced defects and surface recombination at the open sidewalls. Optical investigations of narrow overgrown wires show a significant enhancement (up to two orders of magnitude) of the photoluminescence intensity. This is due to the disappearance of the open sidewalls and carrier capture from the overgrown barrier.From studies of the influence of the crystallographic orientation on the quantum efficiency we find, that <111>B surfaces of the <011> wires offer the best conditions for MBE overgrowth.

Optical Characterization of Compensating Defects in Cubic SiC

2013 ◽  
Vol 740-742 ◽  
pp. 401-404
Author(s):  
Patrik Ščajev ◽  
K. Jarašiūnas ◽  
P.L. Abramov ◽  
S.P. Lebedev ◽  
A.A. Lebedev
Keyword(s):  
Carrier Density ◽  
Nonlinear Optical ◽  
Carrier Lifetime ◽  
Optical Trap ◽  
Optical Characterization ◽  
Carrier Dynamics ◽  
Time Resolved ◽  
Carrier Recombination ◽  
P Type

We present investigation of carrier recombination and optical trap recharge in sublimation grown n- and p-type 3C layers by using time-resolved nonlinear optical techniques. Carrier lifetime and recharged trap recovery were measured by differential transmittivity technique. By monitoring nonequilibrium carrier dynamics, we analyzed impact of carrier density and temperature on carrier lifetime and recharged trap recovery rate. Large carrier lifetime and small diffusivity at low injections in highly compensated samples and their dependences on injection were explained by optical recharge of compensating aluminum impurities. The complete recharge of the compensating impurities by optical means allowed us to calculate the compensating aluminum density in n-type samples and compensating nitrogen in p-type ones.

Optical Characterization of p-Type 4H-SiC Epilayers

2015 ◽  
Vol 821-823 ◽  
pp. 249-252 ◽  
Author(s):  
Gediminas Liaugaudas ◽  
Donatas Dargis ◽  
Pawel Kwasnicki ◽  
Hervé Peyre ◽  
Roxana Arvinte ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Diffusion Length ◽  
Hole Mobility ◽  
Optical Characterization ◽  
Optical Pump ◽  
Time Resolved ◽  
Pump Probe ◽  
Activation Ratio ◽  
P Type

A series of aluminium doped (from 2×1016to 8×1019cm-3) 4H-SiC epitaxial layers were mainly studied by Low Temperature Photoluminescence and time-resolved optical pump-probe techniques to determine the concentration of aluminium, its activation ratio, the doping related carrier lifetime, hole mobility and excess carrier diffusion length.

Characterization of the Excess Carrier Lifetime of As-Grown and Electron Irradiated Epitaxial p-Type 4H-SiC Layers by the Microwave Photoconductivity Decay Method

2010 ◽  
Vol 645-648 ◽  
pp. 207-210 ◽  
Author(s):  
Yoshinori Matsushita ◽  
Masashi Kato ◽  
Masaya Ichimura ◽  
Tomoaki Hatayama ◽  
Takeshi Ohshima
Keyword(s):  
Cross Sections ◽  
Carrier Lifetime ◽  
Excitation Density ◽  
Excess Carrier ◽  
Carrier Lifetimes ◽  
Photoconductivity Decay ◽  
Recombination Centers ◽  
P Type ◽  
Capture Cross Sections

We measured the excess carrier lifetimes in as-grown and electron irradiated p-type 4H-SiC epitaxial layers with the microwave photoconductivity decay (-PCD) method. The carrier lifetime becomes longer with excitation density for the as-grown epilayer. This dependence suggests that e ≥h for the dominant recombination center, where e andh are capture cross sections for electrons and holes, respectively. In contrast, the carrier lifetime does not depend on the excitation density for the sample irradiated with electrons at an energy of 160 keV and a dose of 1×1017 cm-2. This may be due to the fact that recombination centers with e <<h were introduced by the electron irradiation or due to the fact that the acceptor concentration was decreased significantly by the irradiation.

Crystal Growth and Electro-optical Characterization of In2Se2.7Sb0.3 Compound

2020 ◽  
Vol 12 (4) ◽  
pp. 04022-1-04022-4
Author(s):  
Piyush Patel ◽  
◽  
S. M. Vyas ◽  
Vimal Patel ◽  
Himanshu Pavagadhi ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Optical Characterization

Optical Characterization of Monodispersed Aaqueous Cu2+-Doped CdS Nanoparticles Prepared Under Microwave Irradiation Conditions

2014 ◽  
Vol 01 (999) ◽  
pp. 1-1
Author(s):  
Wei Zhu ◽  
Qihui Shen ◽  
Xinjian Bao ◽  
Xiao Bai ◽  
Tingting Li ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Optical Characterization ◽  
Cds Nanoparticles
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