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Zhang Z , Remsing RC , Chakraborty H , Gao W , Yuan G , Klein ML , Ren S
Light-induced dilation in nanosheets of charge-transfer complexes
Proc Natl Acad Sci U S A. 2018 Apr 10;115(15) :3776-3781
PMID: 29581284    PMCID: PMC5899485    URL: https://www.ncbi.nlm.nih.gov/pubmed/29581284
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Abstract
We report the observation of a sizable photostrictive effect of 5.7% with fast, submillisecond response times, arising from a light-induced lattice dilation of a molecular nanosheet, composed of the molecular charge-transfer compound dibenzotetrathiafulvalene (DBTTF) and C60 An interfacial self-assembly approach is introduced for the thickness-controlled growth of the thin films. From photoabsorption measurements, molecular simulations, and electronic structure calculations, we suggest that photostriction within these films arises from a transformation in the molecular structure of constituent molecules upon photoinduced charge transfer, as well as the accommodation of free charge carriers within the material. Additionally, we find that the photostrictive properties of the nanosheets are thickness-dependent, a phenomenon that we suggest arises from surface-induced conformational disorder in the molecular components of the film. Moreover, because of the molecular structure in the films, which results largely from interactions between the constituent pi-systems and the sulfur atoms of DBTTF, the optoelectronic properties are found to be anisotropic. This work enables the fabrication of 2D molecular charge-transfer nanosheets with tunable thicknesses and properties, suitable for a wide range of applications in flexible electronic technologies.
Notes
1091-6490 Zhang, Zhuolei Remsing, Richard C Chakraborty, Himanshu Gao, Wenxiu Yuan, Guoliang Klein, Michael L Ren, Shenqiang Journal Article United States Proc Natl Acad Sci U S A. 2018 Mar 26. pii: 1800234115. doi: 10.1073/pnas.1800234115.