Chlorine doped graphene quantum dots: Preparation, properties, and photovoltaic detectors

Abstract

Reduction in dark current using resonant tunneling barriers in quantum dots-in-a-well long wavelength infrared photodetector Appl. Phys. Lett. 93, 131115 (2008); 10.1063/1.2996410Bias and temperature dependence of the escape processes in quantum dots-in-a-well infrared photodetectors Graphene quantum dots (GQDs) are becoming one of the hottest advanced functional materials because of the opening of the bandgap due to quantum confinement effect, which shows unique optical and electrical properties. The chlorine doped GQDs (Cl-GQDs) have been fabricated by chemical exfoliation of HCl treated carbon fibers (CFs), which were prepared from degreasing cotton through an annealing process at 1000 C for 30 min. Raman study shows that both G and 2D peaks of GQDs may be redshifted (softened) by chlorine doping, leading to an n-type doping. The first vertical (Cl)-GQDs based photovoltaic detectors have been demonstrated, both the light absorbing and electron-accepting roles for (Cl)-GQDs in photodetection have been found, resulting in an exceptionally big ratio of photocurrent to dark current as high as $10 5 at room temperature using a 405 nm laser irradiation under the reverse bias voltage. The study expands the application of (Cl)-GQDs to the important optoelectronic detection devices. V C 2014 AIP Publishing LLC.

Tuning the Emission Energy of Chemically Doped Graphene Quantum Dots

“…The C1s spectra were deconvoluted into seven components assigned to C–C sp 2 bonds at 285.0 eV (C1), C–C sp 3 bonds at 285.8 eV (C2), C–N bonds at 287.0 eV (C3), C–Cl bonds at 287.2 eV (C4), C–O–N bonds 288.2 eV (C5), C–O/C–O=O at 289.0 eV (C6), and O–C–O=O bonds at 290.2 eV (C7). These values are consistent with the previously reported values [27,28,29,30]. The C3 component resembles C–N bonds as well as C–N bonds influenced by Cl or O.…”

Tailoring Blue-Green Double Emissions in Carbon Quantum Dots via Co-Doping Engineering by Competition Mechanism between Chlorine-Related States and Conjugated π-Domains

“…In comparison with counterpart bulk composites, the nanostructured materials equipped with large surface area demonstrate the superior optical, magnetic and electrical characteristics [ 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. The N,Cl co-doped CQDs were prepared by a novel and one-pot hydrothermal method: The certain quantity of CA and BD were dissolved in 10 mL deionized water with well-stirring to form a transparent solution.…”

“…They realized the multicolor emission in chlorine-doped CQDs and attributed such novel optical properties to the additional energy levels between C π and C π* introduced by Cl dopants. Zhao et al [ 29 ] then fabricated the chlorine doped CQDs by way of the chemical exfoliation of HCl treated carbon fibers and the related photovoltaic detectors exhibited an exceptionally big ratio of photocurrent to dark current as high as ~105. Although chlorine doping can bring excellent application performance, the relative research works are rather rare due to the big radius mismatch between Cl and C, especially for double heteroatoms co-doping.…”

Laser‐Generated Nanocrystals in Perovskite: Universal Embedding of Ligand‐Free and Sub‐10 nm Nanocrystals in Solution‐Processed Metal Halide Perovskite Films for Effectively Modulated Optoelectronic Performance

“…In brief, 5 mL of the antisolvent of chlorobenzene was subjected to the irradiation of a nonfocused pulsed laser beam (355 nm, 100 mJ pulse cm −2 ), during which the liquid of chlorobenzene changed from colorless to light yellow. [33] We further characterized the colloidal particles by Raman spectroscopy (Figure 1c), showing the typical peaks centered at 1366 and 1588 cm −1 that is attributed to the D and G bands of the carbon dots (CDs), respectively. The high-resolution transmission electron microscopy (HRTEM) analysis shown in Figure 1b revealed the generation of colloidal particles with an average size of 1.8 nm and interlayer space of about 0.213 nm, which corresponds to the (100) lattice fringe of graphite.…”

“…The high-resolution transmission electron microscopy (HRTEM) analysis shown in Figure 1b revealed the generation of colloidal particles with an average size of 1.8 nm and interlayer space of about 0.213 nm, which corresponds to the (100) lattice fringe of graphite. [33] We further characterized the colloidal particles by Raman spectroscopy (Figure 1c), showing the typical peaks centered at 1366 and 1588 cm −1 that is attributed to the D and G bands of the carbon dots (CDs), respectively. The intensity ratio of the D-band to G-band (I D /I G ) is about 0.65, indicating the good crystalline nature of the CDs, [30] which is consistent with the HRTEM result.…”