Graphene Quantum Dot Vertical Cavity Surface-Emitting Lasers

Abstract

Nonzero-bandgap graphene quantum dots (GQDs) are novel optical gain materials promising for solution-processed light sources with high cost efficiency and device performance. Currently, there have only been a few reports on the realization of GQDs-based lasers. Herein, we demonstrate for the first time roomtemperature lasing emission with green gamut from GQDs in a vertical optical cavity composed of Ta 2 O 5 /SiO 2 dielectric distributed Bragg reflectors (DBRs). The lasing is enabled by the unique design of the DBR, which not only provides a wide stopband spectrally overlapping with the emission of the GQDs but also allows high transmittance of optical excitation in the UV-light region. This demonstration is a clear evidence of the use of GQDs as optical gain materials and represents an important step forward toward their potential applications in wide-gamut laser displays and projectors.

Nitrogen-Doped Graphene Quantum Dots for Remarkable Solar Hydrogen Production

“…The spectra were fitted with a biexponential function to generate a slow (τ 1 ) and a fast (τ 2 ) decay component respectively assigned to radiative and nonradiative deactivation processes. − All the fitting results are summarized in Tables and . It should be noted that the thus-obtained fast and slow lifetime values of the present N-GQDs were at the same order of magnitude with those reported in the literature. − This consistency corroborated the validness of the simplified kinetics model considered for N-GQDs. Furthermore, the values of the reduced χ 2 were close to unity, indicating an ideal fitting model with the normal state of the entire set of the data.…”

Broadband Optical Amplification of Waveguide Cut‐Off Mode in Polymer Waveguide Doped with Graphene Quantum Dots

“…[6] It has been demonstrated that the extraction of GQDs or CDs with a small emission wavelength distribution is a possible way to realize a full-color PL with narrow emission spectra [9,22,23] as well as RGB optical amplifications in liquid form and solidstate laser oscillations in a vertical-cavity surface emitting laser configuration. [10,17] In contrast to applications for such monochromatic light-emitting devices, it is also possible to create broadband light sources by mixing GQDs (or CDs) with different emission wavelengths. [10,31] Tian et al presented a CD-based white-light emitting phosphor as a temperature-tunable color converter.…”

“…Furthermore, high photoluminescence quantum yield (PLQY) [ 7–9 ] and optical amplification properties [ 10–13 ] can also be obtained by mixing the GQDs and CDs with organic molecules or polymers, demonstrating a substantial possibility as active media for optical amplifiers and optically pumped lasers. [ 11,14–18 ]…”

“…[ 6 ] It has been demonstrated that the extraction of GQDs or CDs with a small emission wavelength distribution is a possible way to realize a full‐color PL with narrow emission spectra [ 9,22,23 ] as well as RGB optical amplifications in liquid form and solid‐state laser oscillations in a vertical‐cavity surface emitting laser configuration. [ 10,17 ]…”

“…Furthermore, high photoluminescence quantum yield (PLQY) [7][8][9] and optical amplification properties [10][11][12][13] can also be obtained by mixing the GQDs and CDs with organic molecules or polymers, demonstrating a substantial possibility as active media for optical amplifiers and optically pumped lasers. [11,[14][15][16][17][18] When we apply the GQDs and CDs for light-emitting devices, their broadband tunability in emission wavelength over the entire visible region is a unique feature that is hardly found in other material systems. [9,10,[19][20][21][22][23] In GQDs, the surface functional groups have great impact on the emission…”