Abstract: Two-dimensional (2D) transition-metal dichalcogenides have emerged as a promising material system for optoelectronic applications, but their primary figure-of-merit, the room-temperature photoluminescence quantum yield (QY) is extremely poor. The prototypical 2D material, MoS2 is reported to have a maximum QY of 0.6% which indicates a considerable defect density. We report on an air-stable solution-based chemical treatment by an organic superacid which uniformly enhances the photoluminescence and minority carrier lifetime of MoS2 monolayers by over two orders of magnitude. The treatment eliminates defect-mediated non-radiative recombination, thus resulting in a final QY of over 95% with a longest observed lifetime of 10.8±0.6 nanoseconds. Obtaining perfect optoelectronic monolayers opens the door for highly efficient light emitting diodes, lasers, and solar cells based on 2D materials.

Abstract: Two-dimensional (2D) transition-metal dichalcogenides have emerged as a promising material system for optoelectronic applications, but their primary figure-of-merit, the room-temperature photoluminescence quantum yield (QY) is extremely poor. The prototypical 2D material, MoS2 is reported to have a maximum QY of 0.6% which indicates a considerable defect density. We report on an air-stable solution-based chemical treatment by an organic superacid which uniformly enhances the photoluminescence and minority carrier lifetime of MoS2 monolayers by over two orders of magnitude. The treatment eliminates defect-mediated non-radiative recombination, thus resulting in a final QY of over 95% with a longest observed lifetime of 10.8±0.6 nanoseconds. Obtaining perfect optoelectronic monolayers opens the door for highly efficient light emitting diodes, lasers, and solar cells based on 2D materials.

Abstract: A method for preparing a linearly extended supramolecular fiber or a plurality of linearly aligned supramolecular fibers, which comprises the step of allowing supramolecular monomers to be self-assembled in a microfluidic channel.

Abstract: A microfiber showing improved mechanical strength, which comprises a micro gel fiber consisting of collagen gel or the like covered with high strength hydrogel such as alginate gel.

Abstract: A new solar cell comprising a substrate, a VIB metal thin film deposited on the substrate, and a polycrystalline III-V semiconductor thin film deposited on the VIB metal thin film. A method of making a solar cell comprising providing a substrate, depositing a VIB metal thin film on the substrate, and depositing a polycrystalline III-V semiconductor thin film on the VIB metal thin film. In one embodiment, a polycrystalline III-V semiconductor thin film comprising Indium Phosphide (InP) is deposited on a VIB metal thin film comprising Molybdenum (Mo) by Metal Organic Chemical Vapor Deposition (MOCVD). In another embodiment, growth of Indium phosphide (InP) crystals directly on metal foils is described using a method comprising a closed-spaced sublimation (CSS). In another embodiment, both InP nanowires and polycrystalline films were obtained by tuning growth conditions. In another embodiment, utilizing a silicon dioxide mask, selective nucleation of InP on metal substrates was obtained.

Abstract: A method for preparing a linearly extended supramolecular fiber or a plurality of linearly aligned supramolecular fibers, which comprises the step of allowing supramolecular monomers to be self-assembled in a microfluidic channel.

Abstract: A microfiber showing improved mechanical strength, which comprises a micro gel fiber consisting of collagen gel or the like covered with high strength hydrogel such as alginate gel.