The report said that for this type of panel, the long-term target of more than 30 percent is  within reach. The latest lab tests edge ahead of the maximum 28 percent efficiency that perovskite/silicon cells have managed up to this point.

 In this new research, the 29.15 percent efficiency record was managed with a 1 cm x 1 cm (0.4 inch x 0.4 inch) panel, so some serious scaling up will be required. The team says that should be possible, however. After 300 hours of simulated use, the tandem cell retained 95 percent of its original efficiency, which is another promising sign.

The new record was first reported earlier this year, though the peer-reviewed paper detailing the feat has just been published.

The scientists used specially tweaked layer compositions for both connecting the electrode layer and keeping the two types of cell together in order to reach their new record.

The boffins aren't stopping: previous research suggests that tandem solar cell technology should be able to reach efficiency rates of well above 30 percent, and the team says "initial ideas for this are already under discussion."