ZSW and Manz improve CIGS buffer layer to achieve 21% cell efficiency

Facebook
Twitter
LinkedIn
Reddit
Email

The Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) and technology partner, Manz have achieved a small area CIGS cell conversion efficiency of 21%, verified by Fraunhofer ISE. 

ZSW noted that the new CIGS cell architecture incorporated intermediate films (buffer layer) of zinc oxysulfide (front contact) and zinc magnesium oxide, deposited in a chemical bath, instead of cadmium sulfide and zinc oxide buffer layers. 

This article requires Premium SubscriptionBasic (FREE) Subscription

Unlock unlimited access for 12 whole months of distinctive global analysis

Photovoltaics International is now included.

  • Regular insight and analysis of the industry’s biggest developments
  • In-depth interviews with the industry’s leading figures
  • Unlimited digital access to the PV Tech Power journal catalogue
  • Unlimited digital access to the Photovoltaics International journal catalogue
  • Access to more than 1,000 technical papers
  • Discounts on Solar Media’s portfolio of events, in-person and virtual

Or continue reading this article for free

As a result, ZSW achieved a record cadmium-free solar cell with a surface area of 0.5 square centimetres. 

“First and foremost, the buffer layer transmits more light without the cadmium sulphide,” said Prof. Michael Powalla, ZSW board member and head of the photovoltaics division. “In theory, we could use it to achieve even higher efficiency than with previous CIGS cells. The alternative buffer layer and the cadmium sulfide buffer are both deposited in a chemical bath, so a transition to manufacturing is possible without requiring additional processes.”

The improved cell front contact of zinc magnesium oxide replaced a thin zinc oxide film, while the buffer layer of zinc oxide-sulfide was found to be more transparent to light in the blue wavelength range. 

ZSW expects that commercial CIGS thin-film modules made by Manz could be brought to market within a few years.

Read Next

July 7, 2025
In Europe, PV panel prices fell marginally between May and June, leading to a slight downturn in European module buyers’ market confidence.
July 4, 2025
Chinese PV provider Skycorp Solar Group has announced a solar plant acquisition and development strategy following unanimous board approval.
July 4, 2025
Germany’s latest innovation tender has awarded 488MW of co-located capacity, with all the projects being solar PV tied with energy storage.
July 4, 2025
Risen Energy’s mass-produced heterojunction (HJT) modules have reached a cell conversion efficiency of 26.61%, a record figure for the company.
July 4, 2025
The US House of Representatives has passed the final version of the reconciliation bill that is now going to US President Donald Trump’s desk for his signature before its passing.
July 4, 2025
Australian retailer AGL Energy has confirmed its acquisition of South Australia’s Virtual Power Plant (SAVPP) from Tesla.

Subscribe to Newsletter

Upcoming Events

Media Partners, Solar Media Events
September 2, 2025
Mexico City, Mexico
Solar Media Events
September 16, 2025
Athens, Greece
Solar Media Events
September 22, 2025
Bilbao, Spain
Solar Media Events
September 30, 2025
Seattle, USA
Solar Media Events
October 1, 2025
London, UK