Inductively coupled plasma chemical vapour deposited AlO _x/SiN_y layer stacks for applications in high-efficiency industrial-type silicon solar cells

authored by

T. Dullweber, C. Kranz, B. Beier, B. Veith, J. Schmidt, B. F.P. Roos, O. Hohn, T. Dippell, R. Brendel

Abstract

Passivated emitter and rear cells (PERC) are considered to be the next generation of industrial-type screen-printed silicon solar cells. Deposition methods for rear passivation layers have to meet both the high-throughput and low-cost requirements of the PV industry in combination with high-quality surface passivation properties. In this paper, we evaluate and optimise a novel deposition technique for AlO_x passivation layers by applying an inductively coupled plasma (ICP) plasma-enhanced chemical vapour deposition (PECVD) process. The ICP AlO_x deposition process enables high deposition rates up to 5 nm/s as well as excellent surface recombination velocities below 10 cm/s after firing. A fixed negative charge of -4×10¹² cm^-2 is measured for ICP AlO_x single layers with an interface state density of 11.0×10¹¹ eV^-1 cm^-2 at midgap position. When applied to PERC solar cells the ICP AlO_x layer is capped with a PECVD SiN_y layer. We achieve independently confirmed conversion efficiencies of up to 20.1% for large-area (15.6×15.6 cm²) PERC solar cells with screen-printed metal contacts and ICP AlO_x/SiN_y rear side passivation on standard boron-doped Czochralski-grown silicon wafers. The internal quantum efficiency reveals an effective rear surface recombination velocity S_rear of (90±30) cm/s and an internal rear reflectance R_b of (91±1)% which demonstrates the excellent rear surface passivation of the ICP AlO_x/SiN_y layer stack.

Organisation(s)

Solar Energy Section

External Organisation(s)

Institute for Solar Energy Research (ISFH)
Singulus Technologies AG

Type

Article

Journal

Solar Energy Materials and Solar Cells

Volume

112

Pages

196-201

No. of pages

6

ISSN

0927-0248

Publication date

2013

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment, Surfaces, Coatings and Films

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1016/j.solmat.2013.01.036 (Access: Unknown)