24.2% efficient POLO back junction solar cell with an AlO_x/SiN_y dielectric stack from an industrial-scale direct plasma-enhanced chemical vapor deposition system

authored by

Byungsul Min, Verena Mertens, Yevgeniya Larionova, Thomas Pernau, Helge Haverkamp, Thorsten Dullweber, Robby Peibst, Rolf Brendel

Abstract

An aluminum oxide (AlO_x)/silicon nitride (SiN_y) dielectric stack was developed using an industrial plasma-enhanced chemical vapor deposition (PECVD) system with low-frequency (LF) plasma source for the surface passivation of undiffused textured p-type crystalline silicon. The median recombination current density is 4.3 fA cm⁻² as determined from photoconductance decay lifetime measurements and numerical device modeling. To the best of our knowledge, this is the first time to present a high-quality LF-PECVD AlO_x/SiN_y passivation stack on undiffused textured p-type crystalline silicon wafers, which are cleaned with industrial processes using HF, HCl, and O₃. The simulation agrees well with the measured effective carrier lifetime if the velocity parameters of 5.6 cm s⁻¹ for holes and 803 cm s⁻¹ for electrons are applied with a fixed negative charge density of −3 × 10¹² cm⁻². The process integration of developed AlO_x/SiN_y dielectric stack is successfully demonstrated by fabricating p-type back junction solar cells featuring a poly-Si-based passivating contact at the cell rear side. As the best cell efficiency, we achieve 24.2% with an open-circuit voltage of 725 mV on a M2-sized Ga-doped p-type Czochralski-grown Si wafer as independently confirmed by ISFH CalTeC.

Organisation(s)

Institute of Solid State Physics

External Organisation(s)

Institute for Solar Energy Research (ISFH)
Centrotherm International AG

Type

Article

Journal

Progress in Photovoltaics: Research and Applications

Volume

33

Pages

236-244

No. of pages

9

ISSN

1062-7995

Publication date

19.12.2024

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment, Condensed Matter Physics, Electrical and Electronic Engineering

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1002/pip.3828 (Access: Closed)