Fine Control of Photoluminescence and Optical Waveguiding Characteristics of Organic Rubrene Nanorods Using Focused Electron-Beam Irradiation

Abstract

We demonstrate the fine control of the nanoscale photoluminescence (PL) and optical waveguiding characteristics of light-emitting organic rubrene nanorods (NRs) through focused electron-beam (E-beam) irradiation. Nanoscale laser confocal microscope PL intensity and spectra of the focused E-beam-treated compartments of the rubrene NR drastically varied with Ebeam dose, and yellow-white light emission from those compartments with a specific E-beam dose was observed. In optical waveguiding experiments, the propagation characteristics of optical signals along the single NR were dependent on the crystalline structure of the rubrene.For the E-beam treated NR, the waveguiding PL signals along the crystalline a-axis had relatively higher output, indicating the major axis for the optical energy transfer. Additionally, the waveguiding characteristics such as decay constant along the crystalline b-axis and c-axis of the NR considerably varied at the boundary of the E-beam treatment.

Hybrid Characteristics of MoS2 Monolayer with Organic Semiconducting Tetracene and Application to Anti-Ambipolar Field Effect Transistor

“…The charge mobility (μ) can be calculated using the equation μ = (dI D /dV G )/[(W/L)•(C ox V D )], where dI D /dV G is the trans-conductance, W is the channel width, L is the channel length, and C ox is the capacitance of the oxide. 37 The μ values in the n-type regions ① and ④ were determined as 1.80 × 10 −5 and 2.92 × 10 −5 cm 2 /(V s), respectively. In the p-type regions ② and ③, the μ values were determined as 1.40 × 10 −5 and 2.48 × 10 −5 cm 2 /(V s), respectively.…”

“…Details of the nanoscale LCM PL and Raman mapping experiments have been previously reported. 37,38 To investigate the temperature-dependent PL characteristics of MoS 2 , tetracene, and their hybrids from 300 to 77 K, a vacuum chamber (FTMICROHR2, Oxford Instruments) with liquid nitrogen was used. To determine the fluorescence lifetime decays, timeresolved PL (Tr−PL) spectra were measured using an inverted-type scanning confocal microscope (MicroTime-200, Picoquant, Germany) with a 40× objective.…”

“…The LCM PL and Raman mapping spectra of MoS 2 , tetracene, and their hybrids were analyzed using the WITec software. Details of the nanoscale LCM PL and Raman mapping experiments have been previously reported. , …”

Fine Fabrication and Optical Waveguide Characteristics of Hexagonal tris(8-hydroxyquinoline)aluminum(Ⅲ) (Alq3) Crystal

“…From the calculation of the intensity of main PL peaks, the average decay constant for the Alq 3 MCs was estimated to be 0.381 dB/µm. Considering that the propagated optical signal was measured, we suggested that they are a good candidate for potential materials for application in the development of optical communication devices [33,34].…”

Optical Waveguiding along a Sub-100-nm-Width Organic Nanofiber: Significant Effect of Cooling on Waveguiding Properties

“…Among them, organic nanofibers have attracted increasing interest in the past decade. It has been demonstrated by many researchers that single crystalline micro/nanofibers self-assembled from organic molecules act as “active waveguides”, which propagate their fluorescence generated by optical excitation. − The defect-free nature and smooth surfaces of such self-assembled nanofibers lead to millimeter-scale low-loss waveguiding. Furthermore, interactions between the guided light and excitons created in the nanofibers, which give rise to exciton polaritons, leads to favorable optical properties for use of such nanofibers in miniaturized photonic circuits. , The polariton effect results in a substantially large refractive index, enabling a nanofiber with a subwavelength width to guide and manipulate light at the micrometer scale. − …”