Multiphoton Absorption Coefficients of Organic-Inorganic Lead Halide Perovskites CH3NH3PbX3 (X = Cl, Br, I) Single Crystals

Hybrid organic inorganic lead halide perovskites have recorded unprecedented improvement in efficiency as fourth-generation photovoltaic materials. Recently, they have attracted enormous interest in nonlinear optics stemming basically from their excellent optoelectronic properties. Here, we investigate multiphoton absorption (MPA) in high-quality MAPbX(3) (MA = CH3NH3 and X = Cl, Br, I) bulk single crystals synthesized by an inverse temperature crystallization (ITC) method. The two-photon absorption (2PA) coefficients under picosecond pulse excitation are determined to be beta = 23 +/- 2 cm/GW and 9 +/- 1 cm/GW for MAPbI(3) and MAPbBr(3) at lambda = 1064 nm, and 13 +/- 2 cm/GW for MAPbCl(3) at lambda = 532 nm. The 2PA coefficients are comparable to those of conventional semiconductors having similar bandgaps and can be explained by a two-band model. Furthermore, we characterize the three-photon absorption behavior of MAPbCl(3) at lambda = 1064 nm, yielding gamma = 0.05 +/- 0.01 cm(3)/GW(2). The polarization dependence of MPA is also probed to experimentally estimate the degree of anisotropy. The hybrid perovskites are promising materials for nonlinear optical applications due to polarization dependent MPA response and subsequent strong photoluminescence emission, especially for the Br- and I-containing compounds.