Energy transfer driven brightening of MoS2 by ultrafast polariton relaxation in microcavity MoS2/hBN/WS2 heterostructures
Zehua Hu, Tanjung Krisnanda, Antonio Fieramosca, Jiaxin Zhao, Qianlu Sun, Yuzhong Chen, Haiyun Liu, Yuan Luo, Rui Su, Junyong Wang, Kenji Watanabe, Takashi Taniguchi, Goki Eda, Xiao Renshaw Wang, Sanjib Ghosh, K. Dini, D. Sanvitto, T. C. H. Liew, Qihua Xiong
Abstract
Abstract Energy transfer is a ubiquitous phenomenon that delivers energy from a blue-shifted emitter to a red-shifted absorber, facilitating wide photonic applications. Two-dimensional (2D) semiconductors provide unique opportunities for exploring novel energy transfer mechanisms in the atomic-scale limit. Herein, we have designed a planar optical microcavity-confined MoS 2 /hBN/WS 2 heterojunction, which realizes the strong coupling among donor exciton, acceptor exciton, and cavity photon mode. This configuration demonstrates an unconventional energy transfer via polariton relaxation, brightening MoS 2 with a record-high enhancement factor of ~440, i.e., two-order-of-magnitude higher than the data reported to date. The polariton relaxation features a short characteristic time of ~1.3 ps, resulting from the significantly enhanced intra- and inter-branch exciton-exciton scattering. The polariton relaxation dynamics is associated with Rabi energies in a phase diagram by combining experimental and theoretical results. This study opens a new direction of microcavity 2D semiconductor heterojunctions for high-brightness polaritonic light sources and ultrafast polariton carrier dynamics.