Two thioxanthone based acrylated one‐component visible light photoinitiators, 2‐(methyl(4‐((methyl(9‐oxo‐9H‐thioxanthen‐2‐yl)amino)methyl)benzyl)amino)ethyl acrylate (TX‐EA) and ((4‐((methyl(9‐oxo‐9H‐thioxanthen‐2‐yl)amino)methyl)benzyl)azanediyl)bis(ethane‐2,1‐diyl)diacrylate (TX‐BDA), are designed and synthesized. The results of photopolymerization and migration study demonstrate that TX‐EA and TX‐BDA are more effective one‐component visible light photoinitiators for free radical polymerization with excellent migration stability than 4‐((methyl(9‐oxo‐9H‐thioxanthen‐2‐yl)amino)methyl)phenyl acrylate. The mass fraction of the extracted TX‐BDA in a cured 1,6‐hexanediol diacrylate polymer film is as low as 0.55% and the residual amount is estimated to be only 90 ppm. TX‐BDA would have great potential to be used in visible light curing systems, particularly in the food packing or biomedical fields. Results demonstrate that the synergistic effect of hydrogen donors and polymerizable groups in photoinitiator plays an important role in realizing high performance and low migration in photopolymerization system.

Given their nanoscale dimensions, colloidal semiconductor nanocrystals provide unique systems for investigating the dynamics controlling surface chemistry and fundamental issues regarding lattice reorganization upon changes in electron distribution. These systems are particularly amenable to ultrafast electron probes, offering an atomic level picture of the lattice reorganization involved following photoexcitation. Here, we study lead sulfide (PbS) quantum dots with ultrafast electron diffraction to characterize the atomic motions following high-intensity photoexcitation. Short-range nonthermal lattice distortions and increased atomic disorder were observed in PbS colloidal quantum dots ranging from 2.4 to 8.7 nm in size. These effects scaled inversely with size and were less pronounced in nanocrystals with a chloride-containing surface rather than only organic ligands, which is consistent with an effect arising at the surface. The anisotropic, nonthermal lattice disordering occurs preferentially along the (100) crystallographic directions, which could indicate an anisotropic distribution of localized charge between the differing lattice terminations of the {111} and {100} crystal facets. This is consistent with the larger anharmonicity for the lattice potential at lattice sites with reduced ligand coordination relative to the bulk, which has been shown to cause accelerated relaxation into dynamic and static surface trap sites. Through an exploration of quantum dot size and variation in surface termination, this work provides the missing structural details to advance our understanding and control of charge-carrier formation, trapping, and recombination processes in nanoscale semiconductor systems.

Through the subtle modification of the molecular structure, four donor–acceptor type conjugated polymers were designed, and demonstrated very different device performances with the highest photodetectivity achieved up to 6.2 × 1012 Jones.