Surface Recombination Kinetics at the GaAs/Electrolyte Interface via Photoluminescence Efficiency Measurements

1998 ◽  
Vol 102 (35) ◽  
pp. 6766-6773 ◽  
Author(s):  
John F. Kauffman ◽  
Chang Sheng Liu ◽  
Maurice W. Karl
Keyword(s):  
Surface Recombination ◽  
Electrolyte Interface ◽  
Recombination Kinetics ◽  
Photoluminescence Efficiency

RECOMBINATION PARAMETERS OF CdxI1-xSe EPITAXIAL LAYERS FROM THE PHOTOCONDUCTIVE EFFECT

2001 ◽  
Vol 15 (27) ◽  
pp. 1225-1230 ◽  
Author(s):  
GEORGETA CERBANIC ◽  
IOAN BURDA ◽  
SIMION SIMON
Keyword(s):  
Substrate Temperature ◽  
Surface Recombination ◽  
Usual Method ◽  
Structural Defects ◽  
Epitaxial Layers ◽  
Crystal Perfection ◽  
Chemical Impurities ◽  
Complex Correlation ◽  
Gap States ◽  
Recombination Kinetics

The study of lifetimes regarding the recombination of non-equilibrium carriers and their kinetics is essential in order to explain the recombination mechanisms in semiconductors. The study of recombination kinetics and lifetime values in CdSe epitaxial layers is the target of this paper. CdSe layers have been deposited on (0001) mica substrates by vapor epitaxial method. The epitaxial layers contain defects that induce gap states and specific recombination kinetics. The lifetimes were determined by photoconductive frequency-resolved spectroscopy (PCFRS), a usual method for such measurements. The lifetime spectra obtained show in all studied samples the presence of three types of recombinations: τ1 is due to band-to-band recombination, τ2 to surface recombination associated with chemical impurities and τ3 to surface recombination associated with structural defects. The lifetime measured as a function of the substrate temperature denotes a complex correlation between the crystal perfection and the growth temperature.

Sulfidization in Alcoholic Solutions: A New Surface Passivation Method for GaAs

1995 ◽  
Vol 378 ◽  
Author(s):  
Vasily N. Bessolov ◽  
Andrew F. Ivankov ◽  
Elena V. Konenkova ◽  
Mikhail V. Lebedev
Keyword(s):  
Dielectric Constant ◽  
Laser Irradiation ◽  
Surface Passivation ◽  
Surface Recombination ◽  
Low Dielectric Constant ◽  
New Approach ◽  
Low Dielectric ◽  
Acids And Bases ◽  
Sulfide Solution ◽  
Photoluminescence Efficiency

AbstractA new approach to GaAs surface passivation is suggested which consists in the treatment of GaAs in sulfide solutions in which different alcohols are used as solvents. It has been found that the photoluminescence efficiency of sulfide-treated GaAs associates with the dielectric constant of the solvent being used. With the decrease of dielectric constant value the PL intensity of sulfidized GaAs increases. Sulfidizing in isopropanol-, butanol- or t-butanol-based solutions leads to the formation of sulfide coat which PL properties remain constant even after strong laser irradiation. The effect of the solvent on the GaAs PL efficiensy is explained whithin the framework of hard and soft acids and bases. Thus the use of alcohol-based sulfide solution with low dielectric constant value greatly reduces surface recombination losses in sulfide-treated GaAs.

PHOTOLUMINESCENCE EFFICIENCY AND PHOTOCONDUCTIVITY IN CADMIUM SULFIDE

1967 ◽  
Vol 45 (9) ◽  
pp. 2833-2849 ◽  
Author(s):  
D. W. Nyberg ◽  
K. Colbow
Keyword(s):  
Cadmium Sulfide ◽  
Electric Fields ◽  
Surface Recombination ◽  
Surface Recombination Velocity ◽  
Nonradiative Recombination ◽  
Excitation Light ◽  
Oxygen Ions ◽  
Donor And Acceptor ◽  
Recombination Velocity ◽  
Photoluminescence Efficiency

The photoluminescence efficiency and photoconductivity response of high-purity cadmium sulfide crystals were measured and interpreted in terms of a simple model involving only the donor and acceptor levels previously established, an effective surface recombination velocity, and a bulk nonradiative recombination rate. The measurements at 64 and 78 °K included the effects on the photoluminescence efficiency of varying the excitation intensity and the wavelength of the excitation light, applying electric fields, removing chemically adsorbed oxygen ions from the surface, and of different acceptor concentrations. It was established that the surface does play an important role in reducing the photoluminescence efficiency and photoconductive response, and that the photogenerated carriers do not diffuse significantly into the interior of the crystal.

Surface recombination effects on minority carrier diffusion length measurements using electron beam-induced current

1990 ◽  
Vol 48 (4) ◽  
pp. 744-745
Author(s):  
D.P. Malta ◽  
M.L. Timmons
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Minority Carrier ◽  
Diffusion Length ◽  
Effective Diffusion ◽  
Surface Recombination ◽  
Surface Recombination Velocity ◽  
Logarithmic Scale ◽  
Minority Carrier Diffusion Length ◽  
Carrier Diffusion

Measurement of the minority carrier diffusion length (L) can be performed by measurement of the rate of decay of excess minority carriers with the distance (x) of an electron beam excitation source from a p-n junction or Schottky barrier junction perpendicular to the surface in an SEM. In an ideal case, the decay is exponential according to the equation, I = Ioexp(−x/L), where I is the current measured at x and Io is the maximum current measured at x=0. L can be obtained from the slope of the straight line when plotted on a semi-logarithmic scale. In reality, carriers recombine not only in the bulk but at the surface as well. The result is a non-exponential decay or a sublinear semi-logarithmic plot. The effective diffusion length (Leff) measured is shorter than the actual value. Some improvement in accuracy can be obtained by increasing the beam-energy, thereby increasing the penetration depth and reducing the percentage of carriers reaching the surface. For materials known to have a high surface recombination velocity s (cm/sec) such as GaAs and its alloys, increasing the beam energy is insufficient. Furthermore, one may find an upper limit on beam energy as the diameter of the signal generation volume approaches the device dimensions.

Analysis of the Bias Dependent Spectral Response of a-SiC:H p-i-n Photodiode

2002 ◽  
Vol 715 ◽  
Author(s):  
P. Louro ◽  
A. Fantoni ◽  
Yu. Vygranenko ◽  
M. Fernandes ◽  
M. Vieira
Keyword(s):  
Bias Voltage ◽  
Voltage Dependence ◽  
Spectral Response ◽  
Surface Recombination ◽  
Electrical Field ◽  
Field Reversal ◽  
Current Voltage ◽  
Voltage Dependent ◽  
And Inversion ◽  
Device Operation

AbstractThe bias voltage dependent spectral response (with and without steady state bias light) and the current voltage dependence has been simulated and compared to experimentally obtained values. Results show that in the heterostructures the bias voltage influences differently the field and the diffusion part of the photocurrent. The interchange between primary and secondary photocurrent (i. e. between generator and load device operation) is explained by the interaction of the field and the diffusion components of the photocurrent. A field reversal that depends on the light bias conditions (wavelength and intensity) explains the photocurrent reversal. The field reversal leads to the collapse of the diode regime (primary photocurrent) launches surface recombination at the p-i and i-n interfaces which is responsible for a double-injection regime (secondary photocurrent). Considerations about conduction band offsets, electrical field profiles and inversion layers will be taken into account to explain the optical and voltage bias dependence of the spectral response.

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