Ultrafast Giant Photostriction of Epitaxial Strontium Iridate Film with Superior Endurance.

Yang, Jan-Chi; Liou, Yi-De; Tzeng, Wen-Yen; Liu, Heng-Jui; Chang, Yao-Wen; Xiang, Ping-Hua; Zhang, Zaoli; Duan, Chun-Gang et al. · Nano Lett · 2018

basic_science · Level V

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Abstract

Photostriction, optical stimulus driven mechanical deformation in materials, provides a solution toward next-generation technology. Here, the giant photostriction (∼2% change of lattice) of epitaxial strontium iridate (SrIrO<sub>3</sub>) films under illumination at room temperature is revealed via power-dependent Raman scattering, which is significantly larger as compared to conventional inorganic materials. The time scale and mechanism of this giant photostriction in SrIrO<sub>3</sub> are further studied through time-resolved transient reflectivity measurements. The main mechanism is determined to be the electron-phonon coupling. In addition, we find that such an exotic behavior happens within few picoseconds and remains up to 10<sup>7</sup> cyclic on/off operations. The observation of giant photostriction in SrIrO<sub>3</sub> films with superior endurance promises the advance of shape responsive solids that are sensitive to environmental stimuli, which could be widely utilized for multifunctional optoelectronics and optomechanical devices.