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.