Polarization-selective three-photon absorption and subsequent photoluminescence in CsPbBr3 single crystal at room temperature

초록

We report on highly polarization-selective three-photon absorption (3PA) in a Bridgman-grown single crystal of CsPbBr3 oriented along the (112) direction, which is an inorganic counterpart to emerging organic-inorganic hybrid halide perovskites for solar-cell and optoelectronic applications. The crystal exhibits strong photoluminescence (PL) at room temperature as a direct consequence of 3PA of fundamental radiation. Interestingly, 3PA disappears when the input polarization is parallel to the (-110) direction. This 3PA effect is strongest when orthogonal to (-110) and the corresponding 3PA coefficient was measured to be gamma = 0.14 +/- 0.03 cm(3)/GW(2) under picosecond-pulse excitation at the fundamental wavelength of lambda = 1200 nm. The laser-induced damage threshold was also determined to be about 20 GW/cm(2) at the same wavelength. Based on relative PL intensities upon. tuning over the entire 3PA range (1100-1700 nm), we determined the nonlinear optical dispersion of the 3PA coefficient for CsPbBr3, which is consistent with a theoretical prediction. Experimentally observed significant polarization dependence of. was explained by relevant selection rules. The perovskite is potentially important for nonlinear optical applications owing to its highly efficient 3PA-induced PL response with a sharp on/off ratio by active polarization control.

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