Details
| Original language | English |
|---|---|
| Pages (from-to) | 60-67 |
| Number of pages | 8 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 158 |
| Publication status | Published - 1 Dec 2016 |
Abstract
We present arguments that additional effects besides laterally homogenous tunnelling might occur in carrier-selective poly-Si/c-Si junctions: (i) the symmetrical electrical behaviour of n+ and p+ poly-Si/c-Si junctions, (ii) direct observation of structural modifications of the interfacial oxide upon thermal treatment by transmission electron microscopy, even for poly-Si/c-Si junctions with good passivation quality, and (iii) the achievement of low junction resistances even for interfacial oxide thicknesses >2 nm after thermal treatment. We present an alternative picture, essentially based on a localized current flow through the interfacial oxide, mediated either by local reduction of the oxide layer thickness or by pinholes. In consequence, the local current flow implies transport limitations for both minority and majority carriers in the c-Si absorber, and thus a correlation between recombination current and series resistance. Thus, a poly-Si/c-Si junction can also be explained within the framework of a classical pn junction picture for a passivated, locally contacted emitter, e.g. by the model of Fischer. Both electron selective contacts (n+ poly-Si) and hole selective contacts (p+ poly-Si) can be described consistently when using reasonable input parameters. Especially for p+ poly-Si/c-Si junctions, our model could guideline further improvement.
Keywords
- Modelling, Passivating contact, Passivation, Polysilicon, Silicon solar cell
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Surfaces, Coatings and Films
Sustainable Development Goals
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In: Solar Energy Materials and Solar Cells, Vol. 158, 01.12.2016, p. 60-67.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Working principle of carrier selective poly-Si/c-Si junctions
T2 - Is tunnelling the whole story?
AU - Peibst, R.
AU - Römer, U.
AU - Larionova, Y.
AU - Rienäcker, M.
AU - Merkle, A.
AU - Folchert, N.
AU - Reiter, S.
AU - Turcu, M.
AU - Min, B.
AU - Krügener, J.
AU - Tetzlaff, D.
AU - Bugiel, E.
AU - Wietler, T.
AU - Brendel, R.
N1 - Funding information: This work is mainly performed in the framework of the HERCULES project. HERCULES receives funding from the European Union's Seventh Program for research, technological development and demonstration under grant Agreement no. 608498 . Other parts of the work are funded by the German Ministry for Economic Affairs and Energy under Grants 0325702 (POLO) and 0325478 (SIMPLIHIGH).
PY - 2016/12/1
Y1 - 2016/12/1
N2 - We present arguments that additional effects besides laterally homogenous tunnelling might occur in carrier-selective poly-Si/c-Si junctions: (i) the symmetrical electrical behaviour of n+ and p+ poly-Si/c-Si junctions, (ii) direct observation of structural modifications of the interfacial oxide upon thermal treatment by transmission electron microscopy, even for poly-Si/c-Si junctions with good passivation quality, and (iii) the achievement of low junction resistances even for interfacial oxide thicknesses >2 nm after thermal treatment. We present an alternative picture, essentially based on a localized current flow through the interfacial oxide, mediated either by local reduction of the oxide layer thickness or by pinholes. In consequence, the local current flow implies transport limitations for both minority and majority carriers in the c-Si absorber, and thus a correlation between recombination current and series resistance. Thus, a poly-Si/c-Si junction can also be explained within the framework of a classical pn junction picture for a passivated, locally contacted emitter, e.g. by the model of Fischer. Both electron selective contacts (n+ poly-Si) and hole selective contacts (p+ poly-Si) can be described consistently when using reasonable input parameters. Especially for p+ poly-Si/c-Si junctions, our model could guideline further improvement.
AB - We present arguments that additional effects besides laterally homogenous tunnelling might occur in carrier-selective poly-Si/c-Si junctions: (i) the symmetrical electrical behaviour of n+ and p+ poly-Si/c-Si junctions, (ii) direct observation of structural modifications of the interfacial oxide upon thermal treatment by transmission electron microscopy, even for poly-Si/c-Si junctions with good passivation quality, and (iii) the achievement of low junction resistances even for interfacial oxide thicknesses >2 nm after thermal treatment. We present an alternative picture, essentially based on a localized current flow through the interfacial oxide, mediated either by local reduction of the oxide layer thickness or by pinholes. In consequence, the local current flow implies transport limitations for both minority and majority carriers in the c-Si absorber, and thus a correlation between recombination current and series resistance. Thus, a poly-Si/c-Si junction can also be explained within the framework of a classical pn junction picture for a passivated, locally contacted emitter, e.g. by the model of Fischer. Both electron selective contacts (n+ poly-Si) and hole selective contacts (p+ poly-Si) can be described consistently when using reasonable input parameters. Especially for p+ poly-Si/c-Si junctions, our model could guideline further improvement.
KW - Modelling
KW - Passivating contact
KW - Passivation
KW - Polysilicon
KW - Silicon solar cell
UR - http://www.scopus.com/inward/record.url?scp=84971667640&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2016.05.045
DO - 10.1016/j.solmat.2016.05.045
M3 - Article
AN - SCOPUS:84971667640
VL - 158
SP - 60
EP - 67
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
SN - 0927-0248
ER -