作者
Amani, M.,Lien, D. -H.,Kiriya, D.,Xiao, J.,Azcatl, A.,Noh, J.,Madhvapathy, S. R.,Addou, R.,KC, S.,Dubey, M.,Cho, K.,Wallace, R. M.,Lee, S. -C.,He, J. -H.,Ager, J. W.,Zhang, X.,Yablonovitch, E.,Javey, A.
摘要
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 low. The prototypical 2D material molybdenum disulfide (MoS2) is reported to have a maximum QY of 0.6%, which indicates a considerable defect density. Here 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 more than two orders of magnitude. The treatment eliminates defect-mediated nonradiative recombination, thus resulting in a final QY of more than 95%, with a longest-observed lifetime of 10.8 ± 0.6 nanoseconds. Our ability to obtain optoelectronic monolayers with near-perfect properties opens the door for the development of highly efficient light-emitting diodes, lasers, and solar cells based on 2D materials.