Long-Lived Color-Tunable Room-Temperature Phosphorescence of Boron-Doped Carbon Dots

Abstract

Carbon dots (CDs) with long-lived room-temperature phosphorescence (RTP) or long afterglow properties draw much attention. However, most room-temperature phosphorescent materials are metal containing, and the exploitation of long-lived color-tunable RTP materials faces great challenges. Here, we report metal-free borondoped CDs (B-CDs) for room-temperature phosphorescence with tunable color and an ultralong lifetime. B-CDs were obtained by simply calcining a mixture of boric acid and 1,3,5-benzenetricarboxylic acid in the atmosphere. The as-prepared B-CDs were characterized through UV−vis spectroscopy, photoluminescence spectroscopy, and so forth. Under the excitation of 310 nm UV light, B-CDs show RTP that appears as blue with a phosphorescence lifetime of 1042 ms, and after switching the excited wavelength to 365 nm, the RTP appears as green with a phosphorescence lifetime of 590 ms. Due to the unique RTP properties, B-CDs display promising applications in anticounterfeiting and information encryption.

Switching between Fluorescence and Room Temperature Phosphorescence in Carbon Dots: Key Role of Heteroatom Functionalities

“…19 Furthermore, the triplet excitons can be preserved by incorporating the heteroatom functionalized CDs inside a matrix which can suppress the nonradiative decay processes. 20,21 There are few reports of embedding the CDs into a rigid matrix, e.g., poly(vinyl alcohol) (PVA), 4 polymers, 22 zeolites, 23 urea/biurate, 24 silica, 25 B 2 O 3 , 26 etc., that stabilizes the triplet excitons, and the nonradiative decay rates become suppressed. As a result, RTP can be observed.…”

“…To resolve this, several strategies have been already exhibited. , Among all, controlling heteroatom functionalities can be one of the best strategies. , Heteroatom doping favors populating the triplet state which can increase ISC by facilitating the n−π* transition . Furthermore, the triplet excitons can be preserved by incorporating the heteroatom functionalized CDs inside a matrix which can suppress the nonradiative decay processes. , There are few reports of embedding the CDs into a rigid matrix, e.g., poly­(vinyl alcohol) (PVA), polymers, zeolites, urea/biurate, silica, B 2 O 3 , etc., that stabilizes the triplet excitons, and the nonradiative decay rates become suppressed. As a result, RTP can be observed.…”

Phosphorus and Nitrogen Codoped Carbonized Polymer Dots with Multicolor Room Temperature Phosphorescence for Anticounterfeiting Painting

“…As the reaction time increases, further reactions occur on the intertwined polymer chains of the carbon core; meanwhile, the CO bonds gradually decreased during the reaction period. The CO bonds, as the critical luminescent center, played a very vital role in the color regulation of RTP, which had been clearly mentioned in many previous literature studies. ,,− The CO bonds on the CPDs surface promoted intersystem crossover (ISC), induced the intermolecular electron coupling, and formed surface oxidation triplet states with long-wavelength phosphorescence emission. When the microwave reaction time was short, there were many CO bonds on the CPDs surface, which favored ISC for long-wavelength phosphorescence emission.…”

Evolution and fabrication of carbon dot-based room temperature phosphorescence materials

“…Realizing the final application is the value of a material. 110,126,127,[144][145][146][147][148][149][150] information encryption, 113,115,118,119,121,123,128,[151][152][153][154][155][156][157][158][159][160] sensor detection, 114,124,129,130,147,[161][162][163][164][165][166][167][168][169][170][171][172][173][174] LEDs, [175][176][177][178]…”