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Title: Luminescence methodology to determine grain-boundary, grain-interior, and surface recombination in thin-film solar cells

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.5042532· OSTI ID:1477833
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  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Centre for Nanoscience and Nanotechnology, CNRS, University Paris-Sud/Paris-Saclay, 91460 Marcoussis, France
  3. Univ. of Paris-Sud, Orsay (France)
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We determine the grain-boundary (GB) recombination velocity, SGB, and grain-interior (GI) lifetime, tGI, parameters in superstrate CdS/CdTe thin-film solar cell technology by combining cathodoluminescence (CL) spectrum imaging and time-resolved photoluminescence (TRPL) measurements. We consider critical device formation stages, including after CdTe deposition, CdCl2 treatment, and Cu diffusion. CL image analysis methods extract GB and GI intensities and grain size for hundreds of grains per sample. Concurrently, a three-dimensional CL model is developed to simulate the GI intensity as a function of tGI, SGB, grain size, and the surface recombination velocity, Ssurf. TRPL measurements provide an estimate of Ssurf for the CL model. A fit of GI intensity vs. grain size data with the CL model gives a self-consistent and representative set of SGB and tGI values for the samples: SGB (tGI) = 2.6 x 106 cm/s (68-250 ps), SGB(tGI) = 4.1 x 105 cm/s (1.5-3.3 ns), and SGB (tGI) = 5.5 x 105 cm/s (1.0-3.8 ns) for as-deposited, CdCl2-treated, and CdCl2- A nd Cu-treated samples, respectively. Thus, we find that the CdCl2 treatment both helps to passivate GBs and significantly increase the GI lifetime. Subsequent Cu diffusion increases GB recombination slightly and has nuanced effects on the GI lifetime. Finally, as a partial check on the SGB and tGI values, they are input to a Sentaurus device model, and the simulated performance is compared to the measured performance. The methodology developed here can be applied broadly to CdTe and CdSeTe thin-film technology and to other thin-film solar cell materials including Cu(In1-xGax)Se2, Cu2ZnSnS4, and perovskites.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
Grant/Contract Number:
AC36-08GO28308; 30297; 30300
OSTI ID:
1477833
Alternate ID(s):
OSTI ID: 1471258
Report Number(s):
NREL/JA-5K00-71546
Journal Information:
Journal of Applied Physics, Vol. 124, Issue 11; ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 22 works
Citation information provided by
Web of Science

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Cited By (4)

Radiative Efficiency and Charge‐Carrier Lifetimes and Diffusion Length in Polycrystalline CdSeTe Heterostructures journal December 2019
Exceeding 20% efficiency with in situ group V doping in polycrystalline CdTe solar cells journal August 2019
Recombination and bandgap engineering in CdSeTe/CdTe solar cells journal July 2019
Radiative Efficiency and Charge‐Carrier Lifetimes and Diffusion Length in Polycrystalline CdSeTe Heterostructures journal January 2020

Figures / Tables (18)

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Table II(p. 18)table Table II
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Table III(p. 20)table Table III
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14 SOLAR ENERGY
36 MATERIALS SCIENCE
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crystallographic defects
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