Requires Subscription: Photovoltaics International Archive

Cleaning for high-efficiency solar cell processes

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

By Eckard Wefringhaus, Director of the Quality Management Department, ISC Konstanz; Florian Buchholz, Quality Management Department, ISC Konstanz

This paper discusses the role of wafer cleaning in solar cell processing, and addresses its increasing importance with the introduction of new process steps for manufacturing high-efficiency solar cells. The requirements for
cleaning before several process steps, in relationship to the solar cell production sequence, are discussed: frontend- of-the-line (FEOL) cleaning needs to reduce metal surface concentrations by several orders of magnitude (residues from wafer sawing), while back-end-of-the-line (BEOL) cleaning needs to reduce mostly process induced contamination, which tends to be much lower. A ten-step roadmap for process integration and
optimization of new cleaning processes from lab to fab is suggested, which is based on process analytics and simple bath-lifetime simulations. A number of advanced cleaning steps are identified and their suitability for
solar cell mass production is examined. The influence of the different input variables is demonstrated, with a focus on feed and bleed settings. Finally, the need for constant monitoring of cleaning baths is highlighted, and
a device developed by Metrohm for cost-effective on-site monitoring of metallic contamination is discussed.

L3dwLWNvbnRlbnQvdXBsb2Fkcy9sZWdhY3ktcHVibGljYXRpb24tcGRmcy9iYzFlZGJkY2IwLWNsZWFuaW5nLWZvci1oaWdoZWZmaWNpZW5jeS1zb2xhci1jZWxsLXByb2Nlc3Nlcy5wZGY=

Published In

Photovoltaics International Archive
The period of ‘profitless prosperity’ in the PV industry is finally at an end. Throughout 2013, despite continued economic woes, the PV industry has continued to expand and finally become a global industry. Market forecasts indicating that the sector could reach its next 100GW milestone in just the next two years suggest the industry is on the cusp of another period of strong growth. All the signs confirm this is the case, with utilization rates at their highest level since 2010, companies reporting full order books well into next year and the first tentative announcements of factory capacity expansions making the headlines.

Read Next

Photovoltaics International Archive
Photovoltaics International Papers, PV Modules
With mature product offerings now available from several of the leading industrial PV equipment and tool manufacturers, and latest-generation ECAs available from suppliers, this article aims to provide important background information on ECAs, as well as give a brief overview of some of the challenges and cutting-edge developments in ECA-related PV applications.
Photovoltaics International Archive
Cell Processing, Photovoltaics International Papers
This paper reviews those associated fabrication technologies for the mass production of Ni/Cu-plated contacts. The technologies currently in use in the PV industry for plated contacts, as well as the developing technologies having high scaling-up potential, will be reviewed. In addition, the future requirements for plating metallization will be discussed.
Photovoltaics International Archive
Cell Processing, Photovoltaics International Papers
This paper discusses what is actually behind these announcements and how an evolutionary industry sector such as PVis becoming, it seems, decidedly revolutionary with large jumps in efficiency.
Photovoltaics International Archive
Cell Processing, Photovoltaics International Papers
This paper presents an analysis and the results of extensive simulations of the efficiency limits and roadmap to 25.5% of a tunnel oxide passivated contact (TOPCon) solar cell, on the basis of an efficiency level of 25.21% (designed area, identified by ISFH) achieved through three years of continuous technical optimization on a pilot line at Longi.
Photovoltaics International Archive
Cell Processing, Photovoltaics International Papers
The development of new ways of increasing the production throughput for passivated emitter and rear cells (PERCs), as the major solar cell technology in the global market, is an area of great interest to the PV community. This paper presents approaches for significantly increasing the throughput of PERC production processes. The main focus is on the tube furnace processes for the emitter formation and oxidation, with the introduction of the High Temperature Stack Oxidation (HiTSOx) approach. Additional approaches that are currently under investigation at Fraunhofer ISE for increasing the throughput for wet-chemical, printing and laser processes will also be briefly outlined.
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.

Subscribe to Newsletter

Upcoming Events

Solar Media Events
June 7, 2022
Leonardo Royal London City, London, UK
Solar Media Events
June 14, 2022
Napa, USA
Solar Media Events
June 22, 2022
Sheraton Austin Hotel at the Capitol, Austin, Texas