Ligand-Assisted Formation of Graphene/Quantum Dot Monolayers with Improved Morphological and Electrical Properties

Abstract

Hybrid nanomaterials based on graphene and PbS quantum dots (QDs) have demonstrated promising applications in optoelectronics. However, the formation of high-quality large-area hybrid films remains technologically challenging. Here, we demonstrate that ligand-assisted self-organization of covalently bonded PbS QDs and reduced graphene oxide (rGO) can be utilized for the formation of highly uniform monolayers. After the post-deposition ligand exchange, these films demonstrated high conductivity and photoresponse. The obtained films demonstrate a remarkable improvement in morphology and charge transport compared to those obtained by the spin-coating method. It is expected that these materials might find a range of applications in photovoltaics and optoelectronics.

Nanostructured PbS-Doped Inorganic Film Synthesized by Sol-Gel Route

“…The ability to tailor the optical properties by changing the particle size gives QDs materials the potential to solve many of the challenges of luminescence-based temperature sensors. Thus, PbS QDs in graphene oxide and reduced graphene oxide [ 9 ]; PbS QDs emission photoluminescence in the temperature range 4–300 K, emission domain 1000–1200 nm, collected by 514 nm excitation [ 10 ]; PbS QDs emission in the temperature range 100–300 K with PbS QDs between 3–6.5 nm; and emission at 800–1000 nm [ 11 ] and optical fiber luminescent temperature sensors based on QDs [ 12 ] were reported. Higher quantum efficiency due to an increase in oscillator strength gives QDs the potential to rival traditionally used rare-earth ions as optically active centers for thermal sensing.…”

Beyond Charge Transfer: The Impact of Auger Recombination and FRET on PL Quenching in an rGO-QDs System

“…QD/graphene systems are a type of novel nanostructure with advanced properties that can potentially be used for optoelectronic applications [ 11 , 12 ]. QD/graphene composites can be applied as a top layer in a solar cell to significantly enhance the device’s stability by reducing moisture ingress [ 13 ].…”

Ligand-Assisted Growth of Nanowires from Solution

“…Semiconducting nanoparticles, nanoplatelets and nanowires (nanofibers) are at the heart of modern optoelectronics and photovoltaics [1][2][3][4][5][6][7][8][9][10][11][12][13]. Therefore, the fabrication of such structures with controllable sizes and size distributions is amongst the highest priorities to improving the functional properties of multiple nanodevices.…”

“…Fabrication methodology of semiconducting nanoparticles (quantum dots) [2,9,[14][15][16][17][18] as well as that of anisotropic objects like nanoplatelets [3,5,6,10,[19][20][21][22][23] and nanowires [7,8,11,13,24,25] are in continuous development. A very promising bottom-up fabrication approach is based on molecular ligand-assisted growth (LAG) from the appropriate solutions [12,18,23,26,27]. Interaction of various molecular ligands with nanomaterial surfaces are reviewed in [28], and their role in the synthesis of nanoparticles is described in [29].…”