Two-Dimensional Graphitic Carbon Nitride for Improving the Performance of Organic Solar Cells.

Organic solar cells (OSCs) have attracted lots of attention owing to their low cost, lightweight, and flexibility properties. Nowadays, the performance of OSCs is continuously improving with the development of active layer materials. However, the traditional hole transport layer (HTL) material Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) presents insufficient conductivity and rapid degradation, which decreases the efficiency and stability of OSCs. To conquer the challenge, the two-dimensional (2D) graphitic carbon nitride (g-C3N4) nanomaterials incorporated into the PEDOT:PSS as hybrid HTL are reported. The addition of g-C3N4 into PEDOT:PSS enables the thickness of the HTL to decrease for enhancing the transmittance of the film and increase the conductivity of PEDOT:PSS. Thus, the device exhibts improved charge transport and suppressed carrier recombination, leading to the increase in short-circuit current density and power conversion efficiency of the devices. This work demonstrates that the incorporation of 2D g-C3N4 into PEDOT:PSS for D18:Y6 and PM6:L8-BO-based OSCs can significantly improve the device efficiency to 17.48% and 18.47% with the enhancement of 7.04% and 8.46%, respectively.

Fluorescence detection of protamine, heparin and heparinase II based on a novel AIE molecule with four carboxyl.

In this research, a new DSA (Distyryl-anthracene) derivative with four carboxyl groups was designed and synthesized. This molecule exhibits aggregation-induced emission property (AIE). With the AIE character, a convenient and sensitive fluorescent probe for the detection of protamine, heparin and heparinase has been developed. The protamine can directly induce the aggregation of probe, which caused by electrostatic attraction. In this way, the turn-on detection of protamine is achieved, and the detection limit is as low as 30 ng mL-1. When heparin appears, the probes will be redisperse in solution, which causes a decrease in fluorescence intensity. Besides, this method also shows good selectivity and sensitivity, and the linear range of heparin is from 0.08 to 8 µg mL-1 with detection limit of 37 ng mL-1. After hydrolyzing heparin by heparinase, the probes rebind with protamine and the fluorescence enhance. The fluorescence enhancement was linearly related to the concentration of heparinase in the range of 0.02-2.0 µg mL-1 and detection limit as low as 143.7 ng mL-1. In addition, the results exhibited that the recovery percentage of heparinase in bovine samples reached to 96-101%.