Twin boundaries enhanced current transport in 14.4%-efficient CdTe solar cells by RF sputtering

ABSTRACTTwo issues relating to the determination of junction position in thin film CdTe solar cells have been investigated. Firstly, the use of a focussed ion beam (FIB) milling as a method of sample preparation for electron beam induced current (EBIC) analysis is demonstrated. It is superior to fracturing methods. High quality secondary electron and combined secondary electron/EBIC images are presented and interpreted for solar cells with CdTe layers deposited by both close space sublimation (CSS) or RF sputtering. Secondly, it was shown that in an RF-sputtered CdTe device, while the photovoltaic junction was buried ~1.1 μm from the metallurgical interface, the shape of the external quantum efficiency (EQE) curve did not indicate the presence of a buried homo-junction. SCAPS modelling was used to verify that EQE curve shapes are not sensitive to junctions buried < 1.5μm from the CdTe/CdS interface.

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Effects of Magnetic Field Configuration on Rf Sputtering for CdS/CdTe Solar Cells

MRS Proceedings ◽

10.1557/proc-426-391 ◽

1996 ◽

Vol 426 ◽

Cited By ~ 1

Author(s):

A. Compaan ◽

M. Shao ◽

A. Fischer ◽

D. Grecu ◽

U. Jayamaha ◽

...

Keyword(s):

Magnetic Field ◽

Solar Cells ◽

Film Growth ◽

Rf Sputtering ◽

Field Configuration ◽

Electrical Performance ◽

Magnetic Field Configuration ◽

Growth Interface ◽

Cdte Solar Cells ◽

Planar Magnetron

AbstractWe report studies of solar cells prepared by rf planar magnetron sputtering in which the films were deposited using magnetic field structures ranging from approximately balanced to strongly unbalanced in the “type II” configuration. For films grown with the unbalanced configurations, we find much stronger photoluminescence and much better cell performance than for the balanced configuration. The CdTe films show differences in electrical performance depending on magnetic field as well. These effects are interpreted as arising from the enhanced electron and ion bombardment of the film growth interface for the unbalanced magnetrons. Using two unbalanced magnetrons we have fabricated an all-rf-sputtered cell with NREL-verified efficiency of 11.66% at air mass 1.5 illumination.

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Probing the Correlation of Twin Boundaries and Charge Transport of CdTe Solar Cells Using Electron Backscattering Diffraction and Conductive Atomic Force Microscopy

ACS Applied Energy Materials ◽

10.1021/acsaem.8b00382 ◽

2018 ◽

Vol 1 (8) ◽

pp. 3646-3653 ◽

Cited By ~ 1

Author(s):

Hui Li ◽

Paul Harrison ◽

Judy Wu ◽

Huijun Yao

Keyword(s):

Atomic Force Microscopy ◽

Solar Cells ◽

Charge Transport ◽

Conductive Atomic Force Microscopy ◽

Twin Boundaries ◽

Force Microscopy ◽

Cdte Solar Cells ◽

Electron Backscattering ◽

Atomic Force ◽

Electron Backscattering Diffraction

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CdS/CdTe solar cells by RF sputtering and by laser physical vapor deposition

Conference Record of the Twenty Third IEEE Photovoltaic Specialists Conference - 1993 (Cat. No.93CH3283-9) ◽

10.1109/pvsc.1993.347150 ◽

2002 ◽

Cited By ~ 6

Author(s):

A.D. Compaan ◽

C.N. Tabory ◽

Yuxin Li ◽

Zhirong Feng ◽

A. Fischer

Keyword(s):

Solar Cells ◽

Vapor Deposition ◽

Physical Vapor Deposition ◽

Rf Sputtering ◽

Cdte Solar Cells

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Regimes of current transport mechanisms in CdS/CdTe solar cells

Semiconductor Science and Technology ◽

10.1088/1361-6641/ab23b5 ◽

2019 ◽

Vol 34 (7) ◽

pp. 075013 ◽

Cited By ~ 2

Author(s):

H Bayhan ◽

E T Dağkaldıran ◽

J D Major ◽

K Durose ◽

M Bayhan

Keyword(s):

Solar Cells ◽

Current Transport ◽

Transport Mechanisms ◽

Cdte Solar Cells

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Expanded experimental space for luminescence studies of thin film CdS/CdTe solar cells

MRS Proceedings ◽

10.1557/proc-836-l7.4 ◽

2004 ◽

Vol 836 ◽

Author(s):

Scott Feldman ◽

Tim Ohno ◽

Victor Kaydanov ◽

Reuben Collins

Keyword(s):

Solar Cells ◽

Laser Energy ◽

Spatial Inhomogeneity ◽

Band Edge Emission ◽

Spectral Structure ◽

Current Transport ◽

Cdte Solar Cells ◽

Uniform Current ◽

Electrical Bias ◽

Intensity Laser

ABSTRACTWe have explored a large range of experimental space for photoluminescence (PL) and electroluminescence (EL) measurements of CdS/CdTe solar cells. This space includes changes in temperature, injection intensity (laser power for PL, current for EL), electrical bias for PL, and laser energy for PL. Measurements were resolved both spectrally and spatially (2D for EL, 1D for PL). Combination of EL and PL measurements revealed that most spatial inhomogeneity was the result of non-uniform current transport rather than local variations in recombination rate. The greatest spectral resolution was obtained with low temperature EL at low injection rates. High injection EL as well as high forward biased PL suppressed band-edge emission at low temperatures. Spectral structure was found to be greater in EL than in PL. These effects likely originated from preferential current transport along grain boundaries and/or certain grains.

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