SCIENCE METRICS
High-Impact Chemistry From 2005 A look at the most-cited chemistry research from a decade ago, brought to you by C&EN and CAS
Number of citations: 3,708 Senior author: Peidong Yang Institution: University of California, Berkeley Description of work: Developed a dye-sensitized solar cell in which photoexcitation happens in arrays of coated, vertically-oriented nanowires instead of a nonoriented nanoparticle film. The nanowires provide a direct pathway for electron transport to the solar-cell electrode, boosting device performance. PEIDONG YANG
Number of citations: 3,698 Senior author: Yang Yang Institution: University of California, Los Angeles Description of work: Reported a low-cost polymer-based solar cell Transparent polymer solar cell that could be processed in solution and that set an efciency record for converting sunlight to electricity (4.4%). Later impact of work: Yang’s group developed a transparent polymer solar cell in 2012, a key step toward making electricity-generating “smart windows.” Hindsight from Yang Yang: “This work linked a conjugated polymer’s morphology to its photovoltaic properties, and led to further breakthroughs in polymersolar-cell technology.” Citation: Nat. Mater., DOI: 10.1038/nmat1500
Nanowire solar cell array
Number of citations: 1,830 Senior authors: Mohammad K. Nazeeruddin and Michael Grätzel Institution: ETH Lausanne Description of work: Detailed the purification of three dyes commonly used in dye-sensitized solar cells and elaborated the relationship between the dye’s molecular structure and the electronic properties that govern the efciency of these devices. Later impact of work: At Expo Milano in 2015, a large-scale demonstration of Grätzel’s dye-sensitized solar cells occurred where the photovoltaics were integrated into the roof and windows of a pavilion to provide all the energy
ETH LAUSANNE
Later impact of work: Yang and collaborators are now using the core of the technology to develop artificial photosynthesis systems to convert CO2 and water to fuels. Hindsight from Peidong Yang: “The concept of using nanowire arrays as photoelectrodes is being used now by many research groups to exploit solar energy conversion to produce environmentally friendly fuels.” Citation: Nat. Mater., DOI: 10.1038/nmat1387
needed for air-conditioning and lighting (~42.6 kW). Hindsight from Michael Grätzel: Grätzel holding a solar cell “The high number of citations this paper received was a pleasant surprise because it was theory-intensive. This work eventually led to two product lines, flexible solar cells for portable devices and buildingintegrated solar cells.” Citation: J. Am. Chem. Soc., DOI: 10.1021/ja052467l
SOURCE: Chemical Abstracts Service databases NOTE: Review articles were not included in the analysis. Citations were counted on Dec. 16, 2015.
CEN.ACS.ORG
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DECEMBER 21, 2015
YANG YANG
Chemists love receiving citations from their peers. Citations act as a proxy that measures a study’s impact and creativity and the respect the field has for that work. In collaboration with Chemical Abstracts Service (CAS), C&EN analyzed chemistry papers published in 2005 to see which work stood out from the rest of the pack. Here, we highlight the three most-cited papers, all of which detailed innovative discoveries in the field of solar cells.—MITCH GARCIA
