Strong two-photon absorption of Mn-doped CsPbCl3 perovskite nanocrystals

Emerging CsPbX3 (X = Cl, Br, and I) perovskite nanocrystals (NCs) have been demonstrated to be efficient emitters with a high fluorescence quantum yield, making these materials interesting for optical applications as well as for fundamental physics. Interestingly, doping with transition metal ions has been extensively explored as a way of introducing new optical, electronic, and magnetic properties, making perovskite NCs much more functional than their undoped counterparts. However, there have been no reports regarding the nonlinear optical properties of transition metal ion doped perovskite NCs. Herein, by using femtosecond-transient absorption spectroscopy, we have determined the one-photon linear absorption cross-section (similar to 1.42 x 10(-14) cm(2)) of Mn-doped CsPbCl3 NCs (similar to 11.7+/-1.8 nm size, similar to 0.2% doping concentration, and similar to 600 nm emission wavelength). More importantly, their nonlinear optical properties-in particular, the two-photon absorption (TPA) and resultant emission-were investigated. Notably, the NCs exhibit wavelength-dependent TPA with a maximum value up to similar to 3.18 x 10(5) GM at a wavelength of 720nm. Our results indicate that Mn-doped CsPbCl3 NCs show promise in nonlinear optical devices and multiphoton fluorescence lifetime imaging. Published by AIP Publishing.