Abstract
In this work, we theoretically studied the optical absorption properties of a layer-stacked cocrystal heterogeneous material Spe-TCNB cocrystal (STC) which is produced by supramolecular self-assembly of organic conjugated monomers SPE and TCNB. The highly ordered aggregate structure in the cocrystal STC will lead to intermolecular interactions such as π∼π, hydrogen bonds and van der Waals forces, resulting in significant charge transfer characteristics and large cross-sectional two-photon absorption characteristics. The physical mechanism of one-photon and two-photon charge transfer of cocrystal molecules is specifically discussed and the interaction between molecules and their role in charge transfer are quantitatively analyzed. We found that the charge transfer between molecular junctions composed of hydrogen bonds is mainly cross-bridge charge transfer, while the charge transfer between molecular junctions caused by accumulation is mainly cross-space charge transfer. This discovery is of great significance to the design of organic photoelectric functional materials.
Highlights
Two-photon absorption (TPA), a third-order nonlinear optical effect [1,2] has many potential applications in physics [3], chemistry [4,5], and life sciences [6,7], where TPA can be used to excite high-excitation energy systems at long wavelengths for nondestructive photo-catalysis [8,9,10] or to observe physical processes such as two-photon excited fluorescence (TPEF) [11,12,13]
This unit is alternately connected by two Spe and two TCNBs to form a layered structure
There are three kinds of intermolecular interactions in the intercepted Spe-TCNB cocrystal (STC) periodic unit (Table 1), among which the interlayer interaction comes from two Spe monomers
Summary
Two-photon absorption (TPA), a third-order nonlinear optical effect [1,2] has many potential applications in physics [3], chemistry [4,5], and life sciences [6,7], where TPA can be used to excite high-excitation energy systems at long wavelengths for nondestructive photo-catalysis [8,9,10] or to observe physical processes such as two-photon excited fluorescence (TPEF) [11,12,13]. TPEF is a good in vivo bioassay because long-wave light penetrates well into skin tissue. For the application of TPA, it is essential to discuss the intermolecular TPA charge transfer properties between molecules, even in molecular crystals
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
