Author Affiliations
Abstract
1 College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
2 Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
3 College of Arts and Science, Shanghai Dianji University, Shanghai 201306, China
4 e-mail: chenr@sustech.edu.cn
5 e-mail: tche@szu.edu.cn
In this work, one kind of type II ZnSe/CdS/ZnS core/shell/shell nanocrystals (NCs) is synthesized, and their linear and nonlinear photophysical properties are investigated. Through measurements of the temperature-dependent photoluminescence spectra of NCs, their excitonic properties, including the coefficient of the bandgap change, coupling strength of the exciton acoustic phonons, exciton longitudinal optical (LO) phonons, and LO–phonon energy are revealed. Femtosecond transient absorption spectroscopy was employed to obtain insight into ultrafast processes occurring at the interface of ZnSe and CdS, such as those involving the injection of photo-induced electrons into the CdS shell, interfacial state bleaching, and charge separation time. At the end, their multiphoton absorption spectra were determined by using the z-scan technique, which yielded a maximum two-photon absorption cross section of 3717 GM at 820 nm and three-photon absorption cross section up to at 1220 nm, respectively. The photophysical properties presented here may be important for exploiting their relevant applications in optoelectronic devices and deep-tissue bioimaging.
Photonics Research
2020, 8(9): 09001416
Author Affiliations
Abstract
College of Physics and Energy, Shenzhen University, Shenzhen 518060, China
We have studied the two- and three-photon absorption (2PA and 3PA) properties of Mn-doped CsPbCl3 two-dimensional nanoplatelets (2D NPs) and cubic nanocrystals. Compared with their cubic counterparts, the Mn-doped 2D NPs exhibit stronger quantum confinement effects that can more efficiently enhance their dopant-carrier exchange interactions and multiphoton absorption. More specifically, the maximum volume-normalized 2PA and 3PA cross sections of the 2D NPs were 6.8 and 7.2 times greater than those of their cubic counterparts, respectively, reaching up to 1237 GM/nm3 in the visible light band and 2.24×10 78 cm6·s2·photon 2/nm3 in the second biological window, respectively.
Photonics Research
2018, 6(11): 11001021
Author Affiliations
Abstract
1 College of Physics and Energy, Shenzhen University, Shenzhen 518060, China
2 Department of Electrical and Electronic Engineering, South University of Science and Technology of China, Shenzhen 518055, China
3 Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
Perovskite nanocrystals (NCs) have strong nonlinear optical responses with a number of potential applications, ranging from upconverted blue-lasing to the tagging of specific cellular components in multicolor fluorescence microscopy. Here, we determine the one-photon linear absorption cross section of two kinds of blue-emitting perovskite NCs, i.e., CsPbCl3 and CsPb(Cl0.53Br0.47)3, by utilizing femtosecond transient absorption spectroscopy. The wavelength-dependent nonlinear refraction and two-photon absorption have been measured at wavelengths from 620 to 720 nm by performing Z-scan measurements. The nonlinear optical responses of CsPb(Cl0.53Br0.47)3 are much more pronounced than those of CsPbCl3 due to the larger structural destabilization of the former.
Ultrafast nonlinear optics Ultrafast spectroscopy Photonics Research
2018, 6(6): 06000554
