Surface Passivation Schemes for High-Efficiency c-Si Solar Cells - A Review

Balaji, Nagarajan; Hussain, Shahzada Qamar; Park, Cheolmin; Raja, Jayapal; Yi, Junsin; Jeyakumar, R.

doi:10.4313/teem.2015.16.5.227

Cited by 23 publications

(9 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For complimentary reviews covering the advancements in the 1980–1990s, we suggest the work of Aberle , and for more recent yet more focussed works see Refs. . The subsections to follow concentrate on the S eff metric for the different passivation schemes reviewed, and where data are available a differentiation between chemical and FEP is drawn.…”

Section: Materials and Methods For Silicon Surface Passivationmentioning

confidence: 99%

Dielectric surface passivation for silicon solar cells: A review

Bonilla

Hoex

Hamer

et al. 2017

Physica Status Solidi (a)

235

161

View full text Add to dashboard Cite

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Silicon wafer solar cells continue to be the leading photovoltaic technology, and in many places are now providing a substantial portion of electricity generation. Further adoption of this technology will require processing that minimises losses in device performance. A fundamental mechanism for efficiency loss is the recombination of photo-generated charge carriers at the unavoidable cell surfaces. Dielectric coatings have been shown to largely prevent these losses through a combination of different passivation mechanisms. This review aims to provide an overview of the dielectric passivation coatings developed in the past two decades using a standardised methodology to characterise the metrics of surface recombination across all techniques and materials. The efficacy of a large set of materials and methods has been evaluated using such metrics and a discussion on the current state and prospects for further surface passivation improvements is provided.

show abstract

Section: Materials and Methods For Silicon Surface Passivationmentioning

confidence: 99%

Dielectric surface passivation for silicon solar cells: A review

Bonilla

Hoex

Hamer

et al. 2017

Physica Status Solidi (a)

235

161

View full text Add to dashboard Cite

show abstract

“…It is known that the surface passivation can be achieved by means of two different strategies [1][2][3][4][5][6][7]. The first of them, called chemical passivation, refers to the reduction of interface state density (D it ) at the silicon surface, which can be achieved, for example, through the passivation of silicon dangling bonds by hydrogen atoms.…”

Section: Introductionmentioning

confidence: 99%

“…Among the common passivation materials, the Al 2 O 3 one is currently gaining relevance [1][2][3][4][5][6][7][8][9][10][11], since the passivation by Al 2 O 3 thin films, particularly by Al 2 O 3 deposited by the atomic layer deposition (ALD) technique, is typically a combination of both chemical and field-effect passivation mechanisms [2,3]. This material contains a very high density of negative charges-high Q f -and, as an inherent effect of the ALD technique, the deposited material acts as a hydrogen reservoir providing hydrogen atoms to the Si/SiO x /Al 2 O 3 interface formed or restructured during thermal treatments, thus reducing D it .…”

Section: Introductionmentioning

confidence: 99%

Main properties of Al2O3 thin films deposited by magnetron sputtering of an Al2O3 ceramic target at different radio-frequency power and argon pressure and their passivation effect on p-type c-Si wafers

et al. 2016

View full text Add to dashboard Cite

In this work, 50-nm thick Al 2 O 3 thin films were deposited at room temperature by magnetron sputtering from an Al 2 O 3 ceramic target at different RF power and argon pressure values. The sputtering technique could be preferred to conventional atomic layer deposition for an industrial application, owing to its simplicity, availability, and higher deposition rate. The resulting thin films were characterized by UV/Vis/NIR spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The deposited Al 2 O 3 material was always highly transparent and amorphous in nature. It was found that the O/Al ratio is higher when the Al 2 O 3 layer is deposited at lower RF power or higher argon pressure. Also, some argon incorporation into the films was observed at low deposition pressure. On the other hand, the performance of the previously characterized Al 2 O 3 thin films in the passivation of 2.25-Ωcm p-type float zone c-Si wafer surfaces was evaluated by the quasi-steady-state photoconductance technique. The best effective carrier lifetime value at one-sun illumination, 0.34 ms (corresponding to a surface recombination velocity of 41 cm/s), was obtained with the 50-nm Al 2 O 3 deposited at the higher argon pressure studied, 0.67 Pa (5.0 mTorr), with the lowest RF power studied, 150 W (corresponding to a power density of 3.3 W/cm 2), and after an annealing process, in this case at 350 ºC for 20 min with forming gas. It was assumed that the reduction of the surface passivation quality at higher RF power or lower argon pressure is a consequence of an increased surface damage, and, probably, to a decrease of the O/Al ratio of the Al 2 O 3 passivation material. These assumptions were confirmed with the obtainment of a lifetime of 0.73 ms (a surface recombination velocity equal to 19 cm/s) with a simple experiment with Al 2 O 3 deposited with progressively varied sputtering conditions started from minimal silicon surface damage conditions: 50 W (corresponding to a power density of 1.1 W/cm 2) and 6.67 Pa (50 mTorr). Finally, comments about further improvement of the effective lifetime (up to 1.25 ms, corresponding to a surface recombination velocity of 11 cm/s) with preliminary experiments about the incorporation of an intrinsic hydrogenated amorphous silicon interlayer are included.

show abstract

“…A frequently used method is the chemical vapour deposition of a thin intrinsic a-Si:H layer with a thickness of several nanometers, especially relevant for high efficiency heterojunction solar cells. The underlying passivating mechanism is commonly described as chemical passivation through hydrogen with its capability of saturating the dangling silicon bonds [1]. For an even deeper understanding of this mechanism, the determination of the hydrogen concentration c H in such thin a-Si:H layers is crucial.…”

Section: Introductionmentioning

confidence: 99%

Towards a fast determination of the hydrogen concentration in thin passivating a-Si:H layers using GD-OES

Steffens¹,

Hahn²,

Terheiden³

2018

SiliconPV 2019, THE 9TH INTERNATIONAL CONFERENCE ON CRYSTALLINE SILICON PHOTOVOLTAICS

View full text Add to dashboard Cite

In this contribution, the measurement of the hydrogen concentration in thin passivating amorphous silicon (a-Si:H) layers using Glow Discharge Optical Emission Spectroscopy (GD-OES) is suggested. Usually GD-OES hydrogen measurements suffer from additional signals from atmospheric contaminations, especially from H2O desorbed on the surfaces of such thin layers. This issue is addressed by the deposition of a hydrogen-free copper buffer layer on top, which provides a delay between sputtering the sample surface and the a-Si:H layer itself. Thus the signals from the atmospheric contaminations and from the a-Si:H layer itself are separated. The contamination-free hydrogen signals of the thin a-Si:H layers are eventually calibrated to average hydrogen concentrations.

show abstract

Surface Passivation Schemes for High-Efficiency c-Si Solar Cells - A Review

Cited by 23 publications

References 60 publications

Dielectric surface passivation for silicon solar cells: A review

Dielectric surface passivation for silicon solar cells: A review

Main properties of Al2O3 thin films deposited by magnetron sputtering of an Al2O3 ceramic target at different radio-frequency power and argon pressure and their passivation effect on p-type c-Si wafers

Towards a fast determination of the hydrogen concentration in thin passivating a-Si:H layers using GD-OES

Contact Info

Product

Resources

About