Requires Subscription: Photovoltaics International Archive

Potential for mono-cast material to achieve high efficiencies in mass production

Share on facebook
Facebook
Share on twitter
Twitter
Share on linkedin
LinkedIn
Share on reddit
Reddit
Share on email
Email

By Milica Mrcarica, Senior R&D Engineer, Photovoltech NV

Despite the drop in price of silicon wafers, they are still one of the main factors influencing the cost and performance of Si-based solar cells. These two consequences have initiated a growing commercial interest in mono-cast (castmono, mono-like or quasi-mono) Si wafers, supported by R&D in the areas of material characterization, correlation with cell efficiencies, and mono-cast material use in advanced cell technologies. This paper gives a broad overview and comparison of commercially available grades of mono-cast material from different suppliers. The performance of the material from production in high-throughput screen-printing lines, as well as an analysis of the main material characteristics influencing these results, is presented. A characterization using a lifetime tester and a photoluminescence (PL) imaging tool has shown that not only grain boundaries but also dislocations could cause a drop in cell Voc of more than 15mV. Wafers with large surface areas of Si lattice planes, when processed with anisotropic texturing, could yield an increase in Isc greater than 400mA for 6" substrates, as compared to the isotropic-textured equivalents. Furthermore, when a high-grade mono-cast material processed in anisotropic texturing was compared with CZ mono material from the same supplier and of the same resistivity, light-induced degradation (LID), presented as combined Voc and Isc degradation, was only one-third of that in CZ material. However, although mono-cast material has the potential to increase cell line performance to the same level as that gained by important process and technological improvements, it imposes very high requirements for better material sorting in order to achieve stable cell electrical performance and module aesthetics acceptable to the market.

L3dwLWNvbnRlbnQvdXBsb2Fkcy9sZWdhY3ktcHVibGljYXRpb24tcGRmcy9iYjJlN2QxYmQ1LXBvdGVudGlhbC1mb3ItbW9ub2Nhc3QtbWF0ZXJpYWwtdG8tYWNoaWV2ZS1oaWdoLWVmZmljaWVuY2llcy1pbi1tYXNzLXByb2R1Y3Rpb24ucGRm

Published In

Photovoltaics International Archive
For manufacturers who had their heads in the bunker during 2012, fighting falling ASPs and eroding margins, the nineteenth edition brings you details of what lies in store for this coming year. Wright Williams & Kelly return in this issue with their popular analysis of payback on technology buys; crucially they analyze n-type wafers, Al2O3 passivation and copper metallization. SERIS shows us how to achieve 18.7% efficiencies using low-cost etching techniques on diffused wafers. We also have two important technology roundups: CIGS from Helmholtz Berlin, and PV module encapsulation techniques from Fraunhofer ISE.

Read Next

Photovoltaics International Archive
Cell Processing, Photovoltaics International Papers
The holy grail of every solar cell producer is the creation of a lowcost interdigitated back-contact (IBC) solar cell with an efficiency greater than 25%, a goal that can be found in almost every roadmap presentation. In this paper it will be shown that we are not far away from achieving this target, since IBC devices, with different process complexities, are already in production at several companies.
Photovoltaics International Archive
Cell Processing, Photovoltaics International Papers
This paper will accordingly outline the recent activities at CEA-INES concerning the development and understanding of the integration of such shingle cells.
Photovoltaics International Archive
Cell Processing, Photovoltaics International Papers
In this paper, an even greater reduction in wafer thickness, down to 130μm, is evaluated, and the critical steps in terms of breakage rates in cell and module production processes are reviewed. Finally, the mechanical stability and reliability of these thin HJT cells in glass–backsheet and glass–glass module types are addressed.
Photovoltaics International Archive
Cell Processing, Photovoltaics International Papers
This paper provides a short overview of historical developments, presents the main approaches in mass production today, discusses potential process simplifications, and briefly touches upon a key topic for the future, namely reducing the silver (Ag) consumption per cell.
Photovoltaics International Archive
Fab & Facilities, Photovoltaics International Papers
This paper discusses what approaches from the digitalization field can be used quickly and easily to accelerate ramp-up, to analyse overlapping data and to improve production either manually or automatically.
Photovoltaics International Archive
Fab & Facilities, Photovoltaics International Papers
To embrace the terawatt-scale challenge of the PV market growth, a low-carbon and resource-efficient pathway has to be guaranteed. An approach for doing this is to enable market mechanisms that account for the greenhouse gases emissions, and their associated costs, from PV systems and components.

Subscribe to Newsletter

Upcoming Events

Solar Media Events
October 6, 2021
Solar Media Events
October 19, 2021
BRISTOL, UK
Solar Media Events
December 1, 2021