TY - JOUR
T1 - Correlations between structural properties and performance of microcrystalline silicon solar cells fabricated by conventional RF-PECVD
AU - Li, Liwei
AU - Li, Yuan Min
AU - Anna Selvan, J. A.
AU - Delahoy, Alan E.
AU - Levy, Roland A.
N1 - Funding Information:
The authors would like to thank Andrei Foustotchenko for device measurements and other technical assistance. This research has been supported in part by the US DOE under grant no. DE-FG02-00ER45806. Partial support by NREL, under subcontract no. ZDJ-2-30630-28, for the work performed at Energy Photovoltaics, Inc. (EPV) is also gratefully acknowledged.
PY - 2004/11/1
Y1 - 2004/11/1
N2 - In this study, direct structural characterization of μc-Si:H solar cells deposited by conventional RF-PECVD was conducted using Raman spectroscopy, XRD, and AFM. Strong correlations between i-layer structural properties and device performance were established. A wide variety of i-layer microstructures, from mixed-phase Si:H to highly crystalline μc-Si:H, were revealed by Raman scattering. Micro-crystallinity obtained from Raman scattering, presented as Ic/Ia, proved to be sensitive to the microstructure of μc-Si:H i-layers. Strong spatial non-uniformity of i-layer microstructure as well as variations in device performance were observed. It has been demonstrated here that stable, high performance μc-Si:H solar cells can only be obtained with i-layers being μc-Si:H, yet close to the μc-Si:H to mixed-phase Si:H transition edge where an optimum micro-crystallinity range (Ic/I a at around 1.8) was identified. It was shown by XRD experiments that high performance, optimum μc-Si:H solar cells exhibit smaller grain sizes compared to solar cells with i-layers showing higher micro-crystallinity. Correlations among non-uniformity pattern, i-layer micro-crystallinity, and AFM surface morphologies were also observed.
AB - In this study, direct structural characterization of μc-Si:H solar cells deposited by conventional RF-PECVD was conducted using Raman spectroscopy, XRD, and AFM. Strong correlations between i-layer structural properties and device performance were established. A wide variety of i-layer microstructures, from mixed-phase Si:H to highly crystalline μc-Si:H, were revealed by Raman scattering. Micro-crystallinity obtained from Raman scattering, presented as Ic/Ia, proved to be sensitive to the microstructure of μc-Si:H i-layers. Strong spatial non-uniformity of i-layer microstructure as well as variations in device performance were observed. It has been demonstrated here that stable, high performance μc-Si:H solar cells can only be obtained with i-layers being μc-Si:H, yet close to the μc-Si:H to mixed-phase Si:H transition edge where an optimum micro-crystallinity range (Ic/I a at around 1.8) was identified. It was shown by XRD experiments that high performance, optimum μc-Si:H solar cells exhibit smaller grain sizes compared to solar cells with i-layers showing higher micro-crystallinity. Correlations among non-uniformity pattern, i-layer micro-crystallinity, and AFM surface morphologies were also observed.
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U2 - 10.1016/j.jnoncrysol.2004.07.082
DO - 10.1016/j.jnoncrysol.2004.07.082
M3 - Article
AN - SCOPUS:9644307968
SN - 0022-3093
VL - 347
SP - 106
EP - 113
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
IS - 1-3
ER -