University of California

Japan Science and Technology Agency

The University of Tokyo

Daisuke Kiriya

Shoji Takeuchi

Hiroaki Onoe

Ali Javey

Itaru Hamachi

Yukiko Matsunaga

Der-Hsien Lien

Riho Gojo

James Bullock

Midori Negishi

Matin Amani

Masato Ikeda

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, MoSis 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 MoSmonolayers 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&#xb1;0.6 nanoseconds. Obtaining perfect optoelectronic monolayers opens the door for highly efficient light emitting diodes, lasers, and solar cells based on 2D materials.

[object Object]

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.

Process for producing supramolecular fiber

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.

Covered micro gel fiber

Growing community of inventors

Berkeley, CA, United States of America

Daisuke Kiriya