Intrinsic persistent room temperature phosphorescence derived from 1H-benzo[f]indole itself as a guest

The influence of 1H-benzo[f]indole(Bd) and its derivatives on room temperature phosphorescence(RTP)has raised great concern since they were found to significantly affect RTP of the extensively studied carbazole(Cz) derivatives. However, the role of Bd itself existing in Cz-based or other doping systems was still unclear. In order to clarify its intrinsic phosphorescent property, Bd was introduced as a guest into different organic matrixes including substituted Cz derivatives and polymers. The phosphorescence located in 560–620 nm was confirmed to be derived from Bd itself, which can be detected whatever Bd was doped in the crystal or amorphous state of Cz derivatives. The suitable energy gap between Cz derivatives and Bd is the key to achieve ultralong RTP of Bd. Additionally, when doped in polymers with plenty of hydrogen bonds, RTP of Bd with lifetime over 280 ms was easily obtained. Among them, Bd@PHEMA(poly(hydroxyethyl methacrylate) exhibited superior phosphorescence, with yellow afterglow lasting for over 2.5 s. Therefore, this work demonstrated that a new organic RTP phosphor, Bd, is discovered, and ultralong RTP of Bd can be achieved not only doped in Cz derivatives but also in polymers as the hosts.

Review of Research Progress on Concentrated Solar Energy Utilization System

Solar energy is considered to be one of the most promising renewable and sustainable energy sources.The efficient utilization of solar energy has become a major requirement to build a clean and efficient energy system and achieve the goal of carbon neutrality.The utilization of solar radiation mainly adopts two key technologies:concentrating photovoltaic(PV)and concentrated solar power(CSP).Currently,the cost of CSP with heat storage is about 9c/kWh(same as commercial PV systems)and is expected to drop to 5c/kWh by 2030.From a system level,this paper focuses on analyzing,a system for preparing clean solar fuel based on solar thermal fossil energy,the current mainstream concentrated solar thermal power generation system,the complementary utilization system coupled with multiple energy sources,and the efficient and economical multigeneration system.On the basis of this literature review,the key challenges and future development prospects for the application of concentrating solar energy systems are outlined.A concentrated solar utilization system needs to further improve efficiency and reduce costs in order to expand the scale and promote the market,it has far-reaching significance to achieve the goal of efficient utilization of clean fuel and solar energy.