Stability Challenge in Perovskite Solar Cell Technology

[OKIsItJustMe]

http://www.oist.jp/news-center/news/2016/12/23/stability-challenge-perovskite-solar-cell-technology

[font face=Serif]23 Dec 2016
[font size=5]Stability Challenge in Perovskite Solar Cell Technology[/font]

[font size=3]While solar cell technology is currently being used by many industrial and government entities, it remains prohibitively expensive to many individuals who would like to utilize it.. There is a need for cheaper, more efficient solar cells than the traditional silicon solar cells so that more people may have access to this technology. One of the current popular topics in photovoltaic technology research centers around the use of organic-inorganic halide perovskites as solar cells because of the high power conversion efficiency and the low-cost fabrication.

Perovskites are a type of crystalline material that can be formed using a wide variety of different chemical combinations. Of the many different perovskites formulations that can be used in solar cells, the methylammonium lead iodide perovskite (MAPbI₃ ) has been the most widely studied. Solar cells made of this material have been able to reach efficiencies exceeding 20% and are cheaper to manufacture than silicon. However, their short lifespans have prevented them from becoming a viable silicon solar cell alternative. In order to help create better solar cells in the future, members of the Energy Materials and Surface Sciences Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) have been investigating the cause of rapid degradation of these perovskite solar cells (PSCs).

Dr. Shenghao Wang, first author of the publication in Nature Energy, suggests that the degradation of MAPbI₃ perovskites may not be a fixable issue. His research reveals that iodide-based perovskites will universally produce a gaseous form of iodine, I₂, during operation, which in turn causes further degradation of perovskite. While many researchers have pointed to other sources, such as moisture, atmospheric oxygen and heat as the cause of MAPbI₃ degradation, the fact that these solar cells continue to degrade even in the absence of these factors led Wang to believe that a property intrinsic to these PSCs was causing the breakdown of material.

“We found that these PSCs are self-exposed to I₂ vapor at the onset of degradation, which led to accelerated decomposition of the MAPbI₃ perovskite material into PbI₂.” Wang explained, “Because of the relatively high vapor pressure of I₂, it can quickly permeate the rest of the perovskite material causing damage of the whole PSC.

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[eppur_se_muova]

1. Hmmm ... I would think that formation of traces of CH3I is not out of the question either ...

Lead and methyl iodide ... yummy. XP