European commission, recently, have proposed a set of measures for achieving technological leadership in semiconductor technologies and applications. Chips are strategic assets for key industrial value chains and semiconductors are also at the centre of strong geopolitical interests, conditioning countries capacity to act and drive digital. Manufacturing these optoelectronic devices at an industrial scale raises concerns at technological, economic, environmental and political levels. Scientific research focuses on new-generation semiconductors to generate inexpensive and highly efficient photodetectors and photonic devices. This is where this Marie Skłodowska Curie Action (MSCA) project, entitled “Two Dimensional Materials for Photonic Devices (2D_PHOT)” focus on. The project has had a clear perspective regarding this scenario, searching for alternatives to typical material for photovoltaics designing flexible devices based on two dimensional materials. In this context two-dimensional transition metal dichalcogenides (TMDCs), such as MoS2 or MoSe2, appear promising since these materials feature long-term stability and have direct band gap as monolayers, and can be used in electronics as transistors and in optics as emitters and detectors.
The work on TMDCs monolayers is an emerging research and development field since the discovery of the direct bandgap and their potential applications in electronics and valley physics TMDCs are often combined with other 2D materials like graphene and hexagonal boron nitride to make van der Waals heterostructure. These heterostructures need to be optimized to be possibly used as building blocks for a plenty of different devices such as transistors, solar cells, LEDs, photodetectors, fuel cells, photocatalytic or chemical and biosensing devices. However, for photovoltaics, limited thickness absorption constitutes a general challenge for these two-dimensional materials.
The project roadmap included the design, fabrication and characterization of photonic/plasmonic nanostructured based on transition metal dichalcogenides to overcome this limitation integrating photonic design. So, the obtained results have shown that the fabricated nanostructures increase the absorption performance of these TMDCs materials, but also are useful for the designed optical devices as polarizers or transparent electrodes.
