Energy/Hole Transfer Phenomena in Hybrid α-Sexithiophene (α-STH) Nanoparticle–CdTe Quantum-Dot Nanocomposites

Abstract

Considerable attention has been paid to hybrid organic–inorganic nanocomposites for designing new optical materials. Herein, we demonstrate the energy and hole transfer of hybrid hole-transporting α-sexithiophene (α-STH) nanoparticle–CdTe quantum dot (QD) nanocomposites using steady-state and time-resolved spectroscopy. Absorption and photoluminescence studies confirm the loss of planarity of the α-sexithiophene molecule due to the formation of polymer nanoparticles. Upon photoexcitation at 370 nm, a nonradiative energy transfer (73 %) occurs from the hole-transporting α-STH nanoparticles to the CdTe nanoparticles with a rate of energy transfer of 6.13×10⁹ s⁻¹. However, photoluminescence quenching of the CdTe QDs in the presence of the hole-transporting α-STH nanoparticles is observed at 490 nm excitation, which is due to both static-quenching and hole-transfer-based dynamic-quenching phenomena. The calculated hole-transporting rate is 7.13×10⁷ s⁻¹ in the presence of 42×10⁻⁸ M α-STH nanoparticles. Our findings suggest that the interest in α-sexithiophene (α-STH) nanoparticle–CdTe QD hybrid nanocomposites might grow in the coming years because of various potential applications, such as solar cells, optoelectronic devices, and so on.