Electrogenerated Chemiluminescence and Electroluminescence of N‐Doped Graphene Quantum Dots Fabricated from an Electrochemical Exfoliation Process in Nitrogen‐Containing Electrolytes

Abstract

Artificial lighting sourcesa re one of the most important technological developments for our modernl ives; the search for cost-effective and efficient luminophores is therefore crucial to as ustainable future. Graphene quantum dots (GQDs) are carbon-based nanomaterials that exhibit exceptional optical and electronicp roperties, making them a prime candidate for al uminophore in al ight-emitting device. Nitrogen-doped GQDs fabricated from af acile topdown electrochemical exfoliationp rocess with an itrogen-containing electrolyte in this report showed strongp hotoluminescent emission at 450 nm, and electrogenerated chemiluminescence at 660 nm in the presence of benzoyl peroxide as ac oreactant. When introduced into solid-state light-emitting electrochemical cells, for the first time, the GQDs displayed ab road white emission centered at 610 nm, corresponding to Commision Internationale de l'eclairage (CIE) colour coordinates of (0.38, 0.36).

Film Electrochemiluminescence Controlled by Interfacial Reactions Along with Aggregation‐, Matrix‐Coordination‐, and Crystallization‐Induced Emissions

“…The CQD interfacial ECL film mechanisms and half-cell investigations so far allowed Chu and Ding et al to implement the CQD films into an optimized optoelectronic device. [12] Coreactant solution ECL with 5 mM BPO as a coreactant and 0.3 g/L of CQDs revealed a voltage independent emission state with a peak wavelength of 660 nm and an ECL efficiency of 0.01 % relative to Ru(bpy) 3 2 + in the same conditions. The CQDs were then incorporated into the light emitting layer of a light emitting electrochemical cell (LEC) as well as trimethylolpropane ethoxylate (TMPE) and LiTf as a polymer electrolyte where a device schematic is seen in the inset of Figure 5a.…”

“…For film ECL, one must carefully construct films to be conductive commonly using PEDOT or Nafion polymers to facilitate electron transport, [11] or incorporating conductive salts into the film. [12,13] Additionally, electrolyte solutions chosen for film ECL must not dissolve the generated film but still offer strong conductivity from appropriate electrolytes and wide potential windows for film ECL studies.…”

Insights of Shadow Trapping States and Intramolecular Charge Transfer on Simultaneous Redshift and Efficiency Enhancement of Electrochemiluminescence in Carbon Dots

“…The maximum ECL emission wavelength almost kept constant when the potential varied from −1.2 V to −2.0 V (Figure S19), manifesting that there was only one single excited state corresponding to the ECL emission. [53,54] Notably, an evident P-relevant redshift of ECL emission was observed. As shown in Figure 4c and Figure S20, the ECL spectrum of NCDs displayed a maximum emission at about 425 nm, while the PNCDs-1-2 with a small amount of P dopant showed a maximum emission at 535 nm.…”

Graphene Quantum Dots-Based Nanocomposites Applied in Electrochemical Sensors: A Recent Survey

“…Hydrothermal and solvothermal syntheses are the most employed methods to produce GQDs using top-down routes. In addition, chemical or electrochemical exfoliation and cutting methods [52][53][54][55], microwave and ultrasonic syntheses [56][57][58][59], photo-Fenton reactions [60], and lithography [61] are some other methods usually employed [8,11,18]. As the main disadvantage, top-down methods do not enable the precise control of the GQDs morphology and size, and generally, give rise to GQDs with surface defects.…”