Qi Pengfei, Dai Yuchen, Luo Yang, Tao Guangyi, Zheng Liheng, Liu Donglin, Zhang Tianhao, Zhou Jiadong, Shen Bo, Lin Feng, Liu Zheng, Fang Zheyu
School of Physics, State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing, 100871, China.
Institute of Modern Optics, Nankai University, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Tianjin, 300350, China.
Light Sci Appl. 2022 Jun 10;11(1):176. doi: 10.1038/s41377-022-00860-2.
Phonon-assisted upconverted emission is the heart of energy harvesting, bioimaging, optical cryptography, and optical refrigeration. It has been demonstrated that emerging two-dimensional (2D) semiconductors can provide an excellent platform for efficient phonon-assisted upconversion due to the enhanced optical transition strength and phonon-exciton interaction of 2D excitons. However, there is little research on the further enhancement of excitonic upconverted emission in 2D semiconductors. Here, we report the enhanced multiphoton upconverted emission of 2D excitons in doubly resonant plasmonic nanocavities. Owing to the enhanced light collection, enhanced excitation rate, and quantum efficiency enhancement arising from the Purcell effect, an upconverted emission amplification of >1000-fold and a decrease of 2~3 orders of magnitude in the saturated excitation power are achieved. These findings pave the way for the development of excitonic upconversion lasing, nanoscopic thermometry, and sensing, revealing the possibility of optical refrigeration in future 2D electronic or excitonic devices.
声子辅助上转换发射是能量收集、生物成像、光学加密和光制冷的核心。已经证明，新兴的二维（2D）半导体由于二维激子增强的光学跃迁强度和声子-激子相互作用，可以为高效的声子辅助上转换提供一个优异的平台。然而，关于进一步增强二维半导体中激子上转换发射的研究很少。在此，我们报道了在双共振等离子体纳米腔中二维激子增强的多光子上转换发射。由于增强的光收集、增强的激发速率以及珀塞尔效应引起的量子效率增强，实现了上转换发射放大超过1000倍以及饱和激发功率降低2至3个数量级。这些发现为激子上转换激光、纳米级温度测量和传感的发展铺平了道路，揭示了未来二维电子或激子器件中光制冷的可能性。
