Solar Cell Efficiency Growth Aligned With Scientific Research

• A team of 2 professors from the universities of Luxembourg and Utah have published a study on the role of research in helping improve cell efficiency
• They believe each scientific publication helps advance the field a similar amount, backed by the number of researchers, research effectiveness, time and resources available
• These efforts have led to a standardized learning rate that makes it easy to benchmark new and emerging technologies and how this measures up to current commercial technologies

Researchers from the University of Luxembourg and University of Utah have underlined the contribution of scientific research in improving the efficiency of solar cells, thus leading to the creation of a standardized learning rate as a benchmark for new and emerging technologies, with a new PV learning curve calling it efficiency vs effort.

Professor Philip Dale of the University of Luxembourg explains that usually solar cell development over time is considered as leading to improvement in efficiency of solar cell, but what is important is not so much how much time has passed, instead it is the research effort that helps achieve efficiency improvement.

Using cumulative scientific publications as a proxy for total R&D efforts, the team of Dale and Professor Mike Scarpulla of the University of Utah discovered that the efficiency of solar cells improved by 5% for every order of magnitude of published articles.

To increase the cell efficiency from 5% to 10%, 100 publications are needed, and to go further up from 10% to 15%, 1,000 publications are required, as per their research.

They state, "We have made the simplistic assumption that on average each publication advances the field a similar amount." According to their investigation, efficiency improvements correlate to the number of researchers, researcher effectiveness, time spent, and resources available and that 'all of these arguably also correlate with publication volume'.

Stating the example of halide perovskite that has grown significantly over the last decade, the duo believes this rapid growth appears to be accounted for by the willingness of a large number of scientists to continually join and work on the same material system. Next on the agenda of scientists all over the world are tandem cells.

"The consequence of this standardized learning rate is that it is now easy to benchmark new and emerging technologies to see how they measure up to current commercial technologies enabling scientists to focus their efforts on promising candidates," they add.

Learning spillover from non-PV technologies, cross-pollination from other PV technologies, and hidden commercial effort are not accounted for by this metric, add the professors but they argue that this analysis still yields useful and novel insights into PV technology trajectories.

This research of Dale and Scarpulla has been published in the scientific journal Solar Energy Materials and Solar Cells with the title Efficiency versus effort: A better way to compare best photovoltaic research cell efficiencies.