Details
| Original language | English |
|---|---|
| Pages (from-to) | 17975-17986 |
| Number of pages | 12 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 14 |
| Issue number | 15 |
| Early online date | 5 Apr 2022 |
| Publication status | Published - 20 Apr 2022 |
Abstract
Passivating contacts consisting of heavily doped polycrystalline silicon (poly-Si) and ultrathin interfacial silicon oxide (SiOx) films enable the fabrication of high-efficiency Si solar cells. The electrical properties and working mechanism of such poly-Si passivating contacts depend on the distribution of dopants at their interface with the underlying Si substrate of solar cells. Therefore, this distribution, particularly in the vicinity of pinholes in the SiOx film, is investigated in this work. Technology computer-aided design (TCAD) simulations were performed to study the diffusion of dopants, both phosphorus (P) and boron (B), from the poly-Si film into the Si substrate during the annealing process typically applied to poly-Si passivating contacts. The simulated 2D doping profiles indicate enhanced diffusion under pinholes, yielding deeper semicircular regions of increased doping compared to regions far removed from the pinholes. Such regions with locally enhanced doping were also experimentally demonstrated using high-resolution (5-10 nm/pixel) scanning spreading resistance microscopy (SSRM) for the first time. The SSRM measurements were performed on a variety of poly-Si passivating contacts, fabricated using different approaches by multiple research institutes, and the regions of doping enhancement were detected on samples where the presence of pinholes had been reported in the related literature. These findings can contribute to a better understanding, more accurate modeling, and optimization of poly-Si passivating contacts, which are increasingly being introduced in the mass production of Si solar cells.
Keywords
- dopant diffusion, oxide, pinholes, poly-Si passivating contacts, scanning spreading resistance microscopy, Sentaurus Process TCAD
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
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In: ACS Applied Materials and Interfaces, Vol. 14, No. 15, 20.04.2022, p. 17975-17986.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Local Enhancement of Dopant Diffusion from Polycrystalline Silicon Passivating Contacts
AU - Flrat, Meriç
AU - Wouters, Lennaert
AU - Lagrain, Pieter
AU - Haase, Felix
AU - Polzin, Jana Isabelle
AU - Chaudhary, Aditya
AU - Nogay, Gizem
AU - Desrues, Thibaut
AU - Krügener, Jan
AU - Peibst, Robby
AU - Tous, Loic
AU - Sivaramakrishnan Radhakrishnan, Hariharsudan
AU - Poortmans, Jef
N1 - Funding Information: This work was supported by the European Union’s Horizon2020 Programme for research, technological development, and demonstration [Grant 857793] and by the Kuwait Foundation for the Advancement of Sciences [Grant CN18-15EE-01].
PY - 2022/4/20
Y1 - 2022/4/20
N2 - Passivating contacts consisting of heavily doped polycrystalline silicon (poly-Si) and ultrathin interfacial silicon oxide (SiOx) films enable the fabrication of high-efficiency Si solar cells. The electrical properties and working mechanism of such poly-Si passivating contacts depend on the distribution of dopants at their interface with the underlying Si substrate of solar cells. Therefore, this distribution, particularly in the vicinity of pinholes in the SiOx film, is investigated in this work. Technology computer-aided design (TCAD) simulations were performed to study the diffusion of dopants, both phosphorus (P) and boron (B), from the poly-Si film into the Si substrate during the annealing process typically applied to poly-Si passivating contacts. The simulated 2D doping profiles indicate enhanced diffusion under pinholes, yielding deeper semicircular regions of increased doping compared to regions far removed from the pinholes. Such regions with locally enhanced doping were also experimentally demonstrated using high-resolution (5-10 nm/pixel) scanning spreading resistance microscopy (SSRM) for the first time. The SSRM measurements were performed on a variety of poly-Si passivating contacts, fabricated using different approaches by multiple research institutes, and the regions of doping enhancement were detected on samples where the presence of pinholes had been reported in the related literature. These findings can contribute to a better understanding, more accurate modeling, and optimization of poly-Si passivating contacts, which are increasingly being introduced in the mass production of Si solar cells.
AB - Passivating contacts consisting of heavily doped polycrystalline silicon (poly-Si) and ultrathin interfacial silicon oxide (SiOx) films enable the fabrication of high-efficiency Si solar cells. The electrical properties and working mechanism of such poly-Si passivating contacts depend on the distribution of dopants at their interface with the underlying Si substrate of solar cells. Therefore, this distribution, particularly in the vicinity of pinholes in the SiOx film, is investigated in this work. Technology computer-aided design (TCAD) simulations were performed to study the diffusion of dopants, both phosphorus (P) and boron (B), from the poly-Si film into the Si substrate during the annealing process typically applied to poly-Si passivating contacts. The simulated 2D doping profiles indicate enhanced diffusion under pinholes, yielding deeper semicircular regions of increased doping compared to regions far removed from the pinholes. Such regions with locally enhanced doping were also experimentally demonstrated using high-resolution (5-10 nm/pixel) scanning spreading resistance microscopy (SSRM) for the first time. The SSRM measurements were performed on a variety of poly-Si passivating contacts, fabricated using different approaches by multiple research institutes, and the regions of doping enhancement were detected on samples where the presence of pinholes had been reported in the related literature. These findings can contribute to a better understanding, more accurate modeling, and optimization of poly-Si passivating contacts, which are increasingly being introduced in the mass production of Si solar cells.
KW - dopant diffusion
KW - oxide
KW - pinholes
KW - poly-Si passivating contacts
KW - scanning spreading resistance microscopy
KW - Sentaurus Process TCAD
UR - http://www.scopus.com/inward/record.url?scp=85128546886&partnerID=8YFLogxK
U2 - 10.1021/acsami.2c01801
DO - 10.1021/acsami.2c01801
M3 - Article
C2 - 35380425
AN - SCOPUS:85128546886
VL - 14
SP - 17975
EP - 17986
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
SN - 1944-8244
IS - 15
ER -