Singlet Exciton Delocalization in Gold Nanoparticle-Tethered Poly(3-hexylthiophene) Nanofibers with Enhanced Intrachain Ordering

Abstract

We fabricated hybrid poly­(3-hexylthiophene) nanofibers (P3HT NFs) with rigid backbone organization through the self-assembly of P3HT tethered to gold NPs (P3HT-Au NPs) in an azeotropic mixture of tetrahydrofuran and chloroform. We found that the rigidity of the P3HT chains derives from the tethering of the P3HT chains to the Au NPs and the control of the solubility of P3HT in the solvent. This unique nanostructure of hybrid P3HT NFs self-assembled in an azeotropic mixture exhibits significantly increased delocalization of singlet (S1) excitons compared to those of pristine and hybrid P3HT NFs self-assembled in a poor solvent for P3HT. This strategy for the self-assembly of P3HT-Au NPs that generate long-lived S1 excitons can also be applied to other crystalline conjugated polymers and NPs in various solvents and thus enables improvements in the efficiency of optoelectronic devices.

Augmented Photoluminescence in a Conjugated Polymer by the Incorporation of CdSe/CdS Quantum Dots

“…Because a nonlinear process, e.g., singlet–singlet (S 1 ) annihilation, may interrupt the clear analysis of the interaction between the QDs and the P3HT excitons in our hybrid system, we obtained our TA data of the thin films with a pump intensity of 1.58 μJ/cm 2 to confirm the excited-state dynamics of our sample in a linear decay regime . Two photoinduced absorption (PIA) peaks at 950 nm (positive polaron, P + ) and 1300 nm (S 1 exciton) are clearly seen in the TA spectrum at 0.6 ps after the excitation of the neat P3HT film (red in Figure a), which concur with those of previous reports. ,, The two PIA peaks of the P + and S 1 exciton species split after 1 ps (orange in Figure a). The P + peak at 950 nm remains, whereas the S 1 exciton peak at 1320 nm disappears in the TA spectrum at 100 ps after excitation (blue in Figure a).…”

“…Organic–inorganic nanocomposites are extensively studied owing to their potential in optoelectronic applications. − Among these, organic conjugated polymer-based hybrid systems containing plasmonic and semiconducting nanocrystals (NCs) are worth noting because their organic matrices allow large area and low-cost solution processing. , Moreover, conjugated polymers can be facilely constructed into various nanostructures that can then be used to fabricate optoelectronic devices. − In particular, the singlet (S 1 ) excitons of the conjugated polymers can interact with inorganic NCs, resulting in energy flow. Consequently, characteristic photophysical phenomena, such as hot-electron injection and charge or energy transfer, can occur in hybrid systems. ,,,, …”

“…35 The absorption spectra of the films (thin lines on the left of Figure 1e) exhibit three peaks at 520, 550, and 605 nm that are due to the (0−2), (0−1), and (0−0) transitions of the P3HT chains, respectively. 23,26 As the QD content in the films increases, the broad bands below 500 nm gradually increase in the absorption spectra of the hybrid films. This result indicates that the QDs disturbed the crystallization of the P3HT chains in the hybrid films.…”

“…This result indicates that the QDs disturbed the crystallization of the P3HT chains in the hybrid films. 23 In particular, the PL property of hybrid film #2 is intensified compared to that of the neat P3HT film (thick lines on the right of Figure 1e); the PL quantum yield (PLQY) and thickness values of the thin films are listed in Table S1. We obtained the PL spectra of the films under excitation at 520 nm.…”

Catechol as a Universal Linker for the Synthesis of Hybrid Polyfluorene/Nanoparticle Materials

“…This is proven by the recent evolution in which the optoelectronic properties and excellent processability of CPs are found to be a perfect match with the high electron mobility and unique photonic properties of inorganic nanoparticles (NPs). A wide variety of NPs such as TiO 2 , Fe 3 O 4 , SiO 2 , and noble metals such as Au and Ag have all been used to make advanced hybrid CP/NP materials for the enhancement of optoelectronic devices − or the development of theranostics, chemical tongues, and other sensing applications. − However, each application requires a specific CP/NP combination, which in turn requires compatible, specific end-group functionalization of the CP. Although the CTCP mechanism allows for a wide variety of functional end-groups such as amines, thiols, phosphonic acids, cyanoacrylic acid, and trialkoxysilanes, the process of finding a suitable end group that must furthermore be compatible with the actual polymerization reaction (Murahashi, Kumada-Tamao, Negishi, Suzuki–Miyaura, Kosugi-Migita-Stille, etc.)…”