Monolayer transition metal dichalcogenides integrated in optical microcavities host exciton-polaritons as a hallmark of the strong light-matter coupling regime [1]. Analogous concepts for hybrid light-matter systems employing spatially indirect excitons with a permanent electric dipole moment in heterobilayer crystals promise realizations of exciton-polariton gases and condensates with...
Photoactive defect states in semiconducting single-walled carbon nanotubes (CNTs) have the potential to enable novel applications in quantum photonic technologies. While early experiments have established cryogenic CNTs as quantum light emitters [1], more recent work has identified luminescent defect states as sources of single photons up to room temperature [2,3]. For chemically-engineered...
Due to remarkable electrical, thermal, optical and other properties of carbon nanotubes they have attracted significant interest from research groups all over the world. However, to implement them in the real life, we still need better methods to control their structure at the nanoscale and also techniques to turn these highly defined materials into macroscopic ensembles. In this contribution,...
Since liquid-junction perovskite solar cells (PSCs), the development of organo-lead halide perovskite photovoltaics research has gained momentum with the achievement of the solid-state PSCs in 2012. High absorption coefficient, long-range diffusion length and high defect tolerance of PSCs enable remarkable certified power conversion efficiencies (PCEs) over 20%. Although PSCs are proven to be...
An intermediate frequency mode (IFM) of single-walled carbon nanotubes (SWCNTs) has intriguing properties. The IFM originates from a phonon branch that has acoustic nature in graphene, and has non-zero momentum. Phonons with these properties are usually not analyzable with photons. However, the IFM of SWCNTs was successfully observed in prior reports [1, 2]. Remarkable features of the IFM may...
We demonstrate that localized excitons in luminescent carbon nanotubes can be utilized to study electrostatic fluctuations in the nanotube environment with sensitivity down to the elementary charge. By monitoring the temporal evolution of the cryogenic photoluminescence from individual carbon nanotubes grown on silicon oxide and hexagonal boron nitride we characterize the dynamics of charge...
Monochiral (7,5) single walled carbon nanotubes (SWCNTs) are integrated into a field effect transistor device in which the built-in electric field at the nanotube:metal contact allows for exciton separation under external light bias. Variable wavelength spectroscopy and 2D surface mapping of devices consisting of 10 – 20 nanotubes is performed in the visible, and a strong correlation between...
Photoluminescence (PL) spectroscopy is one of the important analysis techniques for the optical properties of single-walled carbon nanotubes (SWNTs). However, PL spectra are measured only from surfactant-wrapped SWNTs [1], suspended SWNTs [2], and vertically-aligned SWNTs [3]. For optical and opto-electronic applications of SWNTs, SWNTs which lie on substrates and emit PL signal are needed. In...
CNT forest of high emissivity, nearly ideal “black-body absorber[1]”, is attracting researchers as a candidate material for the future application of high-sensitive sensor, thermal energy storage device[2], and so on. Recently, metamaterials, electro-magnetic circuit to the incident EM-wave, opened a method to design desired optical properties. We recently reported CNT forest metamaterial in...
Electronic interactions in low-dimensional nanomaterial heterostructures can lead to novel optical responses arising from exciton delocalization over the constituent materials. Similar phenomena have been suggested to arise between closely interacting semiconducting carbon nanotubes of identical structure. Such behavior in carbon nanotubes has potential to generate new exciton physics, impact...
We design high quality factor air-mode nanobeam cavities by finite-difference time-domain simulations, and utilize the cavities to enhance the emission of air-suspended carbon nanotubes [1]. The cavities are fabricated from silicon-on-insulator wafers, and nanotubes are synthesized over the cavities by chemical vapor deposition. Photoluminescence spectroscopy is performed on the devices, where...
