Pulsed Laser Annealed Ga Hyperdoped Poly-Si/SiOx Passivating Contacts for High-Efficiency Monocrystalline Si Solar Cells

Kejun Chen, Enrico Napolitani, Matteo De Tullio, Chun Sheng Jiang, Harvey Guthrey, Francesco Sgarbossa, San Theingi, William Nemeth, Matthew Page, Paul Stradins, Sumit Agarwal, David L. Young

Research output: Contribution to journalArticlepeer-review

1 Scopus Citations

Abstract

Polycrystalline Si (poly-Si)-based passivating contacts are promising candidates for high-efficiency crystalline Si solar cells. We show that nanosecond-scale pulsed laser melting (PLM) is an industrially viable technique to fabricate such contacts with precisely controlled dopant concentration profiles that exceed the solid solubility limit. We demonstrate that conventionally doped, hole-selective poly-Si/SiOx contacts that provide poor surface passivation of c-Si can be replaced with Ga- or B-doped contacts based on non-equilibrium doping. We overcome the solid solubility limit for both dopants in poly-Si by rapid cooling and recrystallization over a timescale of ∼25 ns. We show an active Ga dopant concentration of ∼3 × 1020 cm−3 in poly-Si which is six times higher than its solubility limit in c-Si, and a B dopant concentration as high as ∼1021 cm−3. We measure an implied open-circuit voltage of 735 mV for Ga-doped poly-Si/SiOx contacts on Czochralski Si with a low contact resistivity of 35.5 ± 2.4 mΩ cm2. Scanning spreading resistance microscopy and Kelvin probe force microscopy show large diffusion and drift current in the p-n junction that contributes to the low contact resistivity. Our results suggest that PLM can be extended for hyperdoping of other semiconductors with low solubility atoms to enable high-efficiency devices.

Original languageAmerican English
Article numbere12542
Number of pages12
JournalEnergy and Environmental Materials
Volume6
Issue number3
DOIs
StatePublished - 2023

Bibliographical note

Publisher Copyright:
© 2022 The Authors. Energy & Environmental Materials published by John Wiley & Sons Australia, Ltd on behalf of Zhengzhou University.

NREL Publication Number

  • NREL/JA-5900-85419

Keywords

  • Ga hyperdoping
  • Ga passivating contacts
  • poly-Si/SiO
  • pulsed laser melting
  • silicon solar cell

Fingerprint

Dive into the research topics of 'Pulsed Laser Annealed Ga Hyperdoped Poly-Si/SiOx Passivating Contacts for High-Efficiency Monocrystalline Si Solar Cells'. Together they form a unique fingerprint.

Cite this