Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration

Bibliographic Details
Main Author: Dahal, Lila R.
Language:English
Published: University of Toledo / OhioLINK 2013
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=toledo1365202814
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-toledo13652028142021-08-03T05:21:28Z Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration Dahal, Lila R. Physics real time spectroscopic ellipsometry photovoltaics a-Si:H solar cell deposition phase diagram spatial phase diagram roll-to-roll deposition back-reflector phasmon resonance surface roughness evolution effective medium theory Real time spectroscopic ellipsometry (RTSE), and ex-situ mapping spectroscopic ellipsometry (SE) are powerful characterization techniques capable of performance optimization and scale-up evaluation of thin film solar cells used in various photovoltaics technologies. These non-invasive optical probes employ multichannel spectral detection for high speed and provide high precision parameters that describe (i) thin film structure, such as layer thicknesses, and (ii) thin film optical properties, such as oscillator variables in analytical expressions for the complex dielectric function. These parameters are critical for evaluating the electronic performance of materials in thin film solar cells and also can be used as inputs for simulating their multilayer optical performance.In this Thesis, the component layers of thin film hydrogenated silicon (Si:H) solar cells in the n-i-p or substrate configuration on rigid and flexible substrate materials have been studied by RTSE and ex-situ mapping SE. Depositions were performed by magnetron sputtering for the metal and transparent conducting oxide contacts and by plasma enhanced chemical vapor deposition (PECVD) for the semiconductor doped contacts and intrinsic absorber layers. The motivations are first to optimize the thin film Si:H solar cell in n-i-p substrate configuration for single-junction small-area dot cells and ultimately to scale-up the optimized process to larger areas with minimum loss in device performance. Deposition phase diagrams for both i- and p-layers on 2" x 2" rigid borosilicate glass substrate were developed as functions of the hydrogen-to-silane flow ratio in PECVD. These phase diagrams were correlated with the performance parameters of the corresponding solar cells, fabricated in the Cr/Ag/ZnO/n/i/p/ITO structure. In both cases, optimization was achieved when the layers were deposited in the protocrystalline phase. Identical solar cell structures were fabricated on 6" x 6" borosilicate glass with 256 cells followed by ex-situ mapping SE on each cell to achieve better statistics for solar cell optimization by correlating local structural parameters with solar cell parameters. Solar cells of similar structure were also fabricated on flexible polymer substrates in the roll-to-roll configuration. In this configuration as well, RTSE was demonstrated as an effective process monitoring and control tool for thin film photovoltaics. 2013-07-11 English text University of Toledo / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=toledo1365202814 http://rave.ohiolink.edu/etdc/view?acc_num=toledo1365202814 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Physics
real time spectroscopic ellipsometry
photovoltaics
a-Si:H solar cell
deposition phase diagram
spatial phase diagram
roll-to-roll deposition
back-reflector
phasmon resonance
surface roughness evolution
effective medium theory
spellingShingle Physics
real time spectroscopic ellipsometry
photovoltaics
a-Si:H solar cell
deposition phase diagram
spatial phase diagram
roll-to-roll deposition
back-reflector
phasmon resonance
surface roughness evolution
effective medium theory
Dahal, Lila R.
Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration
author Dahal, Lila R.
author_facet Dahal, Lila R.
author_sort Dahal, Lila R.
title Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration
title_short Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration
title_full Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration
title_fullStr Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration
title_full_unstemmed Spectroscopic Ellipsometry Studies of Thin Film a-Si:H Solar Cell Fabrication by Multichamber Deposition in the n-i-p Substrate Configuration
title_sort spectroscopic ellipsometry studies of thin film a-si:h solar cell fabrication by multichamber deposition in the n-i-p substrate configuration
publisher University of Toledo / OhioLINK
publishDate 2013
url http://rave.ohiolink.edu/etdc/view?acc_num=toledo1365202814
work_keys_str_mv AT dahallilar spectroscopicellipsometrystudiesofthinfilmasihsolarcellfabricationbymultichamberdepositioninthenipsubstrateconfiguration
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