Light-matter interaction can affect the radiative decay rate of excitons and thus the emission quantum yield (QY) of quantum dots (QDs). In this work, light-matter interaction and outcoupling efficiency of QD light-emitting diodes with different structures are investigated experimentally and theoretically. We show that the external quantum efficiency (EQE) of top-emitting devices is higher than that of the bottom-emitting devices, which is mainly due to the stronger light-matter interaction and higher light outcoupling efficiency of the top-emitting structures. In addition, we show that the QY enhancement induced by light-matter interaction is more significant for low-QY QDs. Our results suggest that top-emitting structures are more powerful for improving the EQE of devices built with low-QY QDs.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jpclett.2c02815 | DOI Listing |
Nano Lett
January 2025
Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
Recent experiments have shown that exciton transport can be significantly enhanced through hybridization with confined photonic modes in a cavity. The light-matter hybridization generates exciton-polariton (EP) bands, whose group velocity is significantly larger than the excitons. Dissipative mechanisms that affect the constituent states of EPs, such as exciton-phonon coupling and cavity loss, have been observed to reduce the group velocities in experiments.
View Article and Find Full Text PDFNanoscale
January 2025
State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an, 710049, China.
Two-dimensional (2D) organic-inorganic halide perovskites are promising sensitive materials for optoelectronic applications due to their strong light-matter interactions, layered structure, long carrier lifetime and diffusion length. However, a high gate bias is indispensable for perovskite-based phototransistors to optimize detection performances, since ion migration seriously screens the gate electric field and the deposition process introduces intrinsic defects, which induces severe leakages and large power dissipation. In this work, an ultrasensitive phototransistor based on the (PEA)SnI perovskite and the Al:HfO ferroelectric layer is meticulously studied, working without an external gate voltage.
View Article and Find Full Text PDFNano Lett
January 2025
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC), X5000HUA Córdoba, Argentina.
While intense laser irradiation and moiré engineering have independently proven powerful for tuning material properties on demand in condensed matter physics, their combination remains unexplored. Here we exploit tilted laser illumination to create spatially modulated light-matter interactions, leading to two striking phenomena in graphene. First, using two lasers tilted along the same axis, we create a quasi-1D supercell hosting a network of Floquet topological states that generate controllable and scalable photocurrents spanning the entire irradiated region.
View Article and Find Full Text PDFNano Lett
January 2025
CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China.
Exciton emitters in two-dimensional monolayer transition-metal dichalcogenides (TMDs) provide a boulevard for the emerging optoelectronic field, ranging from miniaturized light-emitting diodes to quantum emitters and optical communications. However, the low quantum efficiency from limited light-matter interactions and harmful substrate effects seriously hinders their applications. In this work, we achieve a ∼438-fold exciton photoluminescence enhancement by constructing a Fabry-Pérot cavity consisting of monolayer WS and a micron-scale hole on the SiO/Si substrate.
View Article and Find Full Text PDFNanotechnology
January 2025
Walker Department of Mechanical Engineering, The University of Texas at Austin, 204 E. Dean Keeton St., Austin, Texas, 78712-1139, UNITED STATES.
Sapphire is an attractive material in photonic, optoelectronic, and transparent ceramic applications that stand to benefit from surface functionalization effects stemming from micro/nanostructures. Here we investigate the use of ultrafast lasers for fabricating nanostructures in sapphire by exploring the relationship between irradiation parameters, morphology change, and selective etching. In this approach an ultrafast laser pulse is focused on the sapphire substrate to change the crystalline morphology to amorphous or polycrystalline, which is characterized by examining different vibrational modes using Raman spectroscopy.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!