Interfacially Bound Exciton State in a Hybrid Structure of Monolayer WS2 and InGaN Quantum Dots

• DOI: 10.1021/acs.nanolett.8b02143
• Publication Date: 2018-08-24T08:36:57Z
• Authors: Guanghui Cheng; Baikui Li; Chunyu Zhao; Xin Yan; Hong Wang; Kei May Lau; Jiannong Wang
• Keywords: 0301 basic medicine; Interfacial state; Condensed Matter - Mesoscale and Nanoscale Physics; Quantum dots; FOS: Physical sciences; 02 engineering and technology; 7. Clean energy; Transition-metal dichalcogenides; 03 medical and health sciences; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); 0210 nano-technology; Photoluminescence

Van der Waals heterostructures usually formed using atomic thin transition metal dichalcogenides (TMDCs) with a direct bandgap in the near-infrared to the visible range are promising candidates for low-dimensional optoelectronic applications. The interlayer interaction or coupling between two-dimensional (2D) layer and the substrate or between adjacent 2D layers plays an important role in modifying properties of the individual 2D material or device performances through Coulomb interaction or forming interlayer excitons. Here, we report the realization of quasi zero-dimensional (0D) photon emission of WS2 in a coupled hybrid structure of monolayer WS2 and InGaN quantum dots (QDs). An interfacial bound exciton, i.e., coupling between excitons in WS2 and the electrons in QDs has been identified. The emission of this interfacial bound exciton inherits the 0-D confinement of QDs as well as the spin-valley physics of excitons in monolayer WS2. The effective coupling between 2D materials and conventional semiconductors observed in this work provides an effective way to realize 0D emission of 2D materials and opens the potential of compact on-chip integration of valleytronics and conventional electronics/optoelectronics.