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 &#945; -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 &#945; -sexithiophene molecule due to the formation of polymer nanoparticles. Upon photoexcitation at 370 nm, a nonradiative energy transfer (73 %) occurs from the hole-transporting &#945; -STH nanoparticles to the CdTe nanoparticles with a rate of energy transfer of 6.13×10<SUP>9</SUP> s<SUP>-1</SUP>. However, photoluminescence quenching of the CdTe QDs in the presence of the hole-transporting &#945; -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 7.13×10<SUP>7</SUP> s<SUP>-1</SUP> in the presence of 42×10<SUP>-8</SUP> M &#945; -STH nanoparticles. Our findings suggest that the interest in α-sexithiophene (&#945; -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