Significantly Enhanced Photoluminescence of Doped Polymer‐Metal Hybrid Nanotubes

Abstract

We report on the significantly enhanced photoluminescence (PL) of hybrid double‐layered nanotubes (HDLNTs) consisting of poly(3‐methylthiophene) (P3MT) nanotubes with various doping levels enveloped by an inorganic, nickel (Ni) metal nanotube. From laser confocal microscopy PL experiments on a single strand of the doped‐P3MT nanotubes and of their HDLNTs, the PL peak intensity of the HDLNT systems increased remarkably up to ∼350 times as the doping level of the P3MT nanotubes of the HDLNTs increased, which was confirmed by measurements of the quantum yield. In a comparison of the normalized ultraviolet and visible absorption spectra of the doped‐P3MT nanotubes and their HDLNTs, new absorption peaks corresponding to surface‐plasmon (SP) energy were created at 563 and 615 nm after the nanoscale Ni metal coating onto the P3MT nanotubes, and their intensity increased on increasing the doping level of the P3MT nanotube. The doping‐induced bipolaron peaks of the HDLNTs of doped‐P3MT/Ni were relatively reduced, compared with those of the doped‐P3MT nanotubes before the Ni coating, due to the charge‐transfer effect in the SP‐resonance (SPR) coupling. Both energy‐transfer and charge‐transfer effects due to SP resonance contributed to the very‐large enhancement of the PL efficiency of the doped‐P3MT‐based HDLNTs.

Tuning and Enhancing Photoluminescence of Light‐Emitting Polymer Nanotubes through Electron‐Beam Irradiation

“…As the doping level of P3MTnanotubes decreased due to the repeating reduction process through CV, the main peak of the LCM PL spectrum was red-shifted and increased about 14 times. [26] The enhancement and red-shift of the LCM PL peaks of the P3MT nanotubes were also observed through a chemical de-doping process by treating NaOH solution (not shown in here). It is noted that the shapes of the LCM PL spectra of the E-beam irradiated P3MT nanotubes were different from those of the electrochemically de-doped ones, which might be due to the conformational modification of the P3MT nanotubes by relatively high energy Ebeam irradiation.…”

“…It is noted that p-p à transition peaks of electrochemically de-doped P3MT nanotubes were not much changed from their original positions. [26] Based on the LCM Raman results of the E-beam irradiated P3MT nanotube in Figure 5, the intensity, line width, and position of the symmetric C a --Cb ring stretching www.afm-journal.de mode at 1441 cm À1 became increased, narrow, and blue-shifted, respectively (see Supporting Information). These results also confirmed the conformational modification from coil-like dominant configuration to mixed coil-like and rod-like configurations through the E-beam irradiation.…”

Massive, eco-friendly, and facile fabrication of multi-functional anodic aluminum oxides: application to nanoporous templates and sensing platforms

“…For the P3MT NWs with an averaged diameter of $250 nm, the p-p* transition peak and broad bipolaron band were observed at 390 nm and $780 nm, respectively. [7][8][9]68 When the diameters of P3MT NWs were decreased from $250 nm to $25 nm, the p-p* transition peak was blue-shied toward 380 nm, and became broadened, particularly enhancing its tail in shorter wavelength region, as shown in Fig. 7d, indicating the reduction of the p-conjugation length due to the conne synthesis within relatively narrow volume of the fabricated AAOs.…”

“…The averaged diameters (f) of the PPy NWs synthesized by using fabricated AAOs were estimated to be $25 nm and $50 nm, which were little bit smaller that D P of the AAOs owing to a tiny gap existing between hydrophilic AAO and hydrophobic organic materials. 7,69 However, those of the PPy NWs synthesized by using purchased AAOs were estimated to be $140 nm and $250 nm, which were much larger than specications provided by the manufacturer. This inconsistency was originated that nanopores in the purchased AAOs showed spheroid-like shape with non-uniform D P , where the D P at the middle of the nanopore would be larger than those at both ends, which would be appropriate for ltering applications.…”

“…[1][2][3][4] Aer the report on the two-step anodization resulting in a distinct improvement of the structural periodicities over the extended spatial regime, 5,6 anodic aluminum oxides (AAOs) have been widely adopted in diverse research elds, such as representative nanoporous templates for one-dimensional (1-dim.) nanostructures, [7][8][9][10][11][12][13] membrane lters, [14][15][16][17] evaporation/etching masks, 18-21 humidity sensors, [22][23][24][25][26][27][28] energy storage devices, [29][30][31][32] and bio-applications, [33][34][35][36] etc. These applications excluding surface treatments require AAOs with freestanding forms, i.e., separation from aluminum (Al) substrate, thus various strategies have been developed in the viewpoints of not only AAO fabricating (anodizing) but also AAO separating procedure.…”