In a breakthrough finding, material scientists at the Samueli School of Engineering UCLA and co-workers from five other universities have discovered the major reason for performance of perovskite solar cells to suffer over time.
This involved successful demonstration of a simple manufacturing adjustment to correct the cause of degradation, and thus clearing the biggest block toward the widespread adoption of thin-film solar cell technology.
A research paper that covers the findings in detail is published in Nature.
Materially, perovskites are a class of materials with same atomic structure or crystal structure as mineral calcium titanium oxide. A subgroup of metal halide perovskites, perovskites are of great interest because of their promising application for energy-efficient thin film type solar cells.
From manufacturing perspective, manufacture of perovskite-based solar cells is feasible at much lower costs than their silicon-based counterparts. This makes solar energy technologies more accessible if the degradation under long exposure to illumination which is commonly known can be properly addressed.
In fact, perovskite-based solar cells exhibit a tendency to degrade in sunlight much faster than the ones made of silicon, and thus their effectiveness to convert sunlight into electricity declines over long term.
Nonetheless, the finding demonstrates the reason behind this and provides a simple correction solution. This represents a major finding for commercialization and widespread adoption of perovskite cells.
A common surface treatment to eliminate solar cells flaws involves depositing a layer of organic ions that causes the surface to be negatively charged too. The team of researchers discovered that while the treatment is intended to improve the efficiency of energy conversion during fabrication, it also unintentionally creates a surface more rich in electron, which works as a potential trap for energy-carrying electrons.