Anomalous photoluminescence emission of monolayer MoS2-QD heterostructure on hBN

TL;DR

This study reports anomalous multiple photoluminescence emission peaks in a MoS2-CdSe QD heterostructure on hBN, revealing complex interactions affecting exciton behavior not seen on SiO2 substrates.

Contribution

It uncovers novel multiple exciton emission peaks in MoS2-QD heterostructures on hBN, highlighting the influence of substrate-induced effects on optical properties.

Findings

Multiple exciton emission peaks observed on hBN, absent on SiO2

Potential role of lattice mismatch and strain in emission behavior

Altered quantum potential of QD due to substrate effects

Abstract

Monolayer transition metal dichalcogenides(2D) and zero dimensional quantum dots(QD) are known to have unique optical properties in their individual limit such as high binding energy of excitons. The combination of these two systems is of particular interest in understanding various aspects of energy transfer, charge transfer, dynamics of excitons, etc. In this manuscript, we report the anomalous photoluminescence(PL) emission in one such heterostructure MoS2-CdSe QD. We observe multiple exciton emission peaks of the heterostructure on hBN substrate which are absent on SiO2. Our observation open up the questions, whether the local potential due to the lattice mismatch between MoS2 and hBN has any role in deciding the emission of these peaks or the strain eld of MoS2 and hBN is the reason for the emergence of multiple emission. In addition, the altered quantum potential of QD due the presence of hBN and MoS2 may also leads to such multiple emissions.