Effective optical generation rate and carrier surface recombination velocities in variband film photodetecting structures of MBE p-MCT

ABSTRACTIn this contribution 1, 2 and 3-dimensional simulations of micromorph silicon solar cells are presented. In order to simulate solar cells with rough interfaces, the surface topographies were measured via atomic force microscopy (AFM) and transferred into the commercial software Sentaurus TCAD (Synopsys). The model of the structure includes layer thicknesses and optoelectronic parameters like complex refractive index and defect structure. Results of the space resolved optical generation rates by using of the optical solver Raytracer are presented. The space resolved optical generation rate inside the semiconductor layers depends on the structure of the transparent conductive oxides (TCO) interface. In this contribution the influence of different optical generation rates on the electrical characteristics of the solar cell device are investigated. Furthermore, the optical and electrical results of the 1D, 2D and 3D structures, which have equal layer thicknesses and optoelectronic parameters, are compared.

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Temperature Dependence of the Growth and Saturation of Light-Induced Defects in a-Si:H

MRS Proceedings ◽

10.1557/proc-219-27 ◽

1991 ◽

Vol 219 ◽

Cited By ~ 3

Author(s):

M. Isomura ◽

N. Hata ◽

S. Wagner

Keyword(s):

Defect Density ◽

Annealing Process ◽

Intensity Dependence ◽

Optical Generation ◽

Defect Sites ◽

Pool Model ◽

Ion Laser ◽

Increasing Temperature ◽

Induced Defects ◽

Optical Generation Rate

ABSTRACTWe report new experimental data on the light-soaking of a-Si:H with a Kr-ion laser at an optical generation rate G of at least 4×1021 to 3×1022 cm-3s1. We studied the temperature and intensity dependence of the saturation of the defect density and found that the saturation value of light-induced defects (Nsat) is insensitive to temperature and light intensity below about 90°C. Above 90°C Nsat drops with increasing temperature. This behavior can be explained within the defect pool model by a limited number of defect sites coupled with an annealing process.

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Influence of laser-pulse shape and surface recombination on the photon generation rate in experiments on the dynamical casimir effect

Journal of Russian Laser Research ◽

10.1007/s10946-010-9177-8 ◽

2010 ◽

Vol 31 (6) ◽

pp. 563-573

Author(s):

Alexander V. Dodonov ◽

Victor V. Dodonov

Keyword(s):

Laser Pulse ◽

Pulse Shape ◽

Casimir Effect ◽

Surface Recombination ◽

Generation Rate ◽

Dynamical Casimir Effect ◽

Laser Pulse Shape ◽

Photon Generation

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017685x ◽

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.

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