Gas chromatography–mass spectrometry analyses of encapsulated stable perovskite solar cells

• Published in: Science (American Association for the Advancement of Science) Vol. 368; no. 6497
• Main Authors: Shi, Lei, Bucknall, Martin P., Young, Trevor L., Zhang, Meng, Hu, Long, Bing, Jueming, Lee, Da Seul, Kim, Jincheol, Wu, Tom, Takamure, Noboru, McKenzie, David R., Huang, Shujuan, Green, Martin A., Ho-Baillie, Anita W. Y.
• Format: Journal Article
• Language: English
• Published: United States The American Association for the Advancement of Science 19.06.2020
• Subjects: Chromatography; Climate; Decomposition; Energy conversion; Gas chromatography; Gases; Heat; Heating; High temperature; Humidity; Mass spectrometry; Mass spectroscopy; Packaging; Perovskites; Photovoltaic cells; Photovoltaics; Polyisobutylene; Polymers; Relative humidity; Scientific imaging; Solar cells; Solar energy; Thermal cycling; Thermal decomposition; Thermal stress
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.aba2412

Solar cells are subject to heating when operating in sunlight, and the organic components of hybrid perovskite solar cells, especially the commonly used methylammonium cation, can undergo thermal decomposition. Encapsulation can limit decomposition by bringing such reactions to equilibrium and can prevent exposure to damaging ambient moisture. Shi et al. examined several encapsulation schemes for perovskite films and devices by probing volatile products with gas chromatography–mass spectrometry (see the Perspective by Juarez-Perez and Haro). Pressure-tight polymer/glass stack encapsulation was effective in suppressing gas transfer and allowed solar cells containing methylammonium to pass harsh moisture and thermal cycling tests. Science , this issue p. eaba2412 ; see also p. 1309 Volatile emissions of encapsulated stable perovskite solar cells that passed harsh humidity and heating tests were analyzed. Although perovskite solar cells have produced remarkable energy conversion efficiencies, they cannot become commercially viable without improvements in durability. We used gas chromatography–mass spectrometry (GC-MS) to reveal signature volatile products of the decomposition of organic hybrid perovskites under thermal stress. In addition, we were able to use GC-MS to confirm that a low-cost polymer/glass stack encapsulation is effective in suppressing such outgassing. Using such an encapsulation scheme, we produced multi-cation, multi-halide perovskite solar cells containing methylammonium that exceed the requirements of the International Electrotechnical Commission 61215:2016 standard by surviving more than 1800 hours of the Damp Heat test and 75 cycles of the Humidity Freeze test.