This year has been huge for solar research achievements increasing cell efficiencies. And it’s not just happening for the ‘next big thing’ which is perovskites, nor only for the various niche or not yet used semiconductors, nor even for the highest-efficiency form of mainstream silicon photovoltaics which is heterojunction – even TOPCon is achieving further gains, and there are some innovations which apply to broad categories of solar technology – so many different things that they need their own article. One of the most eye-catching announcements has been China’s DAS Solar announcement at the recent SNEC conference of a technical roadmap leading from 23% cell efficiency with TOPCon in 2019, to 25.4% with mass-produced TOPCon today (and 26.24% in the…