Periodic Reporting for period 1 - INTRINSIC (INducing TRionic gaIn in two-dimensional semicoNductors by local StraIn and Charge manipulation)
Reporting period: 2022-11-01 to 2024-10-31
The INTRINSIC project (INducing TRionic gaIn in two-dimensional semicoNductors by local StraIn and Charge manipulation) aims to advance excitonic-based optoelectronic devices by controlling excitonic complexes, such as excitons and trions, in 2D semiconductors, particularly transition metal dichalcogenides (TMDCs). The project seeks to achieve precise exciton-to-trion conversion, enabling trionic optical gain and lasing — a mechanism relying on intrinsic exciton-trion interactions upon photoexcitation rather than global population inversion.
To accomplish this, INTRINSIC investigates how excitonic complexes form in TMDCs under morphological and dielectric changes. It focuses as well on designing open optical cavities that can induce both (i) charge confinement effects through strain or charge doping, promoting exciton-to-trion conversion and (ii) laser feedback in targeted spectral regions.
To accomplish this, INTRINSIC investigates how excitonic complexes form in TMDCs under morphological and dielectric changes. It focuses as well on designing open optical cavities that can induce both (i) charge confinement effects through strain or charge doping, promoting exciton-to-trion conversion and (ii) laser feedback in targeted spectral regions.
During the first reporting period, training activities included (i) the exfoliation and characterization of TMDC monolayers and flakes using optical contrast microscopy, photoluminescence micro-spectroscopy, and atomic force microscopy (ii) dry-transfer technique to transfer TMDCs monolayer between different substrates comprising transfer of a TMDC monolayer on a TMDC nanostructured flake, (iii) use of a custom-built optical microscope with spectroscopic capabilities for measuring polarization resolved (both excitation and detection) k-space transmission/reflection and photoluminescence (iv) training on the spectroscopic characterization of laser emission with k-space spectroscopy, (v) procedure for preparing TMDC flakes for electron beam lithography. Supported by Rigorous Coupled Wave Analysis simulations, we designed and fabricated an all-TMDC vertical heterostructure capable of sustaining high-quality-factor photonic resonances. The tunability of these photonic resonances, achieved through precise modification of the heterostructure's geometric parameters, has resulted in altered emission properties. These changes, potentially induced by modifications in the dielectric environment and strain fields, will be key features in achieving trionic lasing. The researcher also published two peer-reviewed journal articles, and delivered to group members four presentation highlighting the results of the research work. The implementation of the INTRINSIC project during the first reporting period has significant improved the researcher’s career prospects by offering a wide range of new skills ranging from advanced nanofabrication, spectroscopic characterization and electromagnetic simulation of nanophotonic devices.
Within the INTRINSIC project, we have developed, during the first reporting period, an all-TMDCs photonic platform based on a vertical heterostructure that can induce modifications to the emission properties of one of its constituents at room temperature, utilizing dielectric effects and potentially doping and strain effects. We anticipate that these photonic heterostructures, along with possible modifications to enhance the quality factor of the photonic resonances, will be crucial for achieving trionic lasing. This process, which will be explored during the return phase, holds significant promise for the development of ultrathin, low-power demanding emission devices, aligning with efforts to reduce energy consumption.