Controlled Synthesis of Long-Wavelength Multicolor-Emitting Carbon Dots for Highly Efficient Tandem Luminescent Solar Concentrators

Abstract

Long-wavelength multicolor emission and high photoluminescence quantum yields (PLQYs) play a key role in carbon dot (CD)-based luminescent solar concentrators (LSCs). Herein, long-wavelength multicolor-emitting CDs with high PLQYs had been synthesized by one-step solvothermal process of phenylenediamine (PD) isomers (m-, o-, p-PDs) in the presence of lignin. Relying on the introduction of lignin, green (G), yellow (Y), and red (R) emissive CDs without excitation wavelength dependence could be achieved. The R, Y, G CDs showed clearly red shift effect in PL emission spectra, compared to the control CDs samples (Rc, Yc, Gc CDs) only based on PD isomers as precursors. The PL red shift probably resulted from the size effect of CDs. Remarkably, the R, Y, G CDs with high PLQYs (15.01, 41.52, and 7.60%) had been achieved owing to their long PL lifetimes, which is also higher than that of control Rc, Yc, Gc CDs samples (PLQYs of 12.66, 38.32, and 3.48%). Moreover, the tandem LSCs based on the R, Y, G CDs had further been demonstrated. The external optical efficiency (η opt ) and power conversion efficiency (η) of LSCs had been enhanced greatly up to 4.03 and 2.92%, respectively, compared to that of LSCs based on the control CDs LSCs (only have 3.76 and 2.66%).

Synthesis, optical properties and applications of red/near-infrared carbon dots

“…C-dots with a 15% of QY, through a one-step solvothermal process using phenylenediamine isomers in the presence of lignin. 50 As shown in Fig. 11a, c C-dots LSCs exhibited wide PL spectra, well matching the Sun's spectrum (Fig.…”

“…Several methods have been used to synthesize crystalline C-dots, such as hydrothermal, solvothermal, microwave-assisted, self-exothermic reaction and pyrolysis methods, 19,50,90,[126][127][128][129][130][131][132][133][134] which are very easy and do not require an air-free reaction system. 19,50,90,[126][127][128][129][130][131][132][133][134] In addition, most of the synthetic routes for C-dots involved the use of cost-effective and earth-abundant precursors. 68,82,111,133 Hence, this section will focus on the synthesis and the related optical properties of red/NIR crystalline C-dots.…”

UV-Filtering Cellulose Nanocrystal/Carbon Quantum Dot Composite Films for Light Conversion in Glass Windows

“…Carbon quantum dots (CDs) have emerged as a new class of carbon nanomaterials for photoluminescent applications. − Its intrinsic merits of excellent optical properties, high stability, low cost, high abundance, environment-friendliness, and biocompatibility have attracted the increasing attention of researchers . In past reports, researchers had designed and synthesized CDs with wide tunable bandgap and high quantum yield by heteroatom doping, surface passivation, size control, and special separation and purification. − However, there were still challenges in the synthesis of CDs with narrow peak widths (fwhm of 29–30 nm) and long emission (>600 nm) wavelengths. , It was a feasible way to utilize the excellent photoluminescence performance of CDs to develop composite materials with light conversion functions for energy-saving buildings …”

Review on Colloidal Quantum Dots Luminescent Solar Concentrators

“…The doping of QDs with other compounds such as organic dyes such as Coumarin or metals such as Cu has resulted in improved optical efficiencies by reducing reabsorption losses and controlling the frequencies of re‐emitted light [69–75] . Different QDs can be used in multi‐layered (tandem) LSC devices to capture a wider frequency range of incident light, thereby improving the overall absorption and decreasing reabsorption [76–79] . The concentration of QDs also directly impacts the efficiency of an LSC.…”