Heterostructures of 2D materials-quantum dots (QDs) for optoelectronic devices: challenges and opportunities

Despite the fact that organic semiconductors have promising properties such as ease of fabrication and low cost, further improvements in the properties and performances of both materials and devices remain necessary. The unique characteristics of two-dimensional (2D) materials including carbon-based nanomaterials, black phosphorus, transition-metal carbides, nitrides, and carbonitrides are the most promising nanomaterials for optoelectronic devices due to their atomic thickness and excellent optical properties. These 2D-layered materials can be combined to form a monolayer (lateral 2D heterostructure) or a multilayer stack (vertical 2D heterostructure). Nevertheless, their light detection efficiency is limited by their low light absorption ability and the rapid recombination of photogenerated electron-hole pairs. Also, recently, it has been discovered that quantum dots (QDs) have excellent local photon capture capabilities which can enhance the overall efficiency of photodetectors in 2D materials. As a result, QDs are integrated with 2D heterostructures to improve the performance of 2D materials and overcome their limitations. Integration of QDs with 2D material enhances electronic performance. In the present review, we have discussed the important properties, synthesis, and optoelectronic applications of 2D materials. This article also provides an overview of state of the art and highlights the promising results of the research field for next-generation heterostructures of 2D materials-QDs. 2D heterostructures with QD composite materials are successfully shown for optoelectronic properties.