Photophysics of pentacene-doped picene thin films

TL;DR

This study investigates how doping picene thin films with pentacene affects their optical properties, revealing efficient energy transfer and enhanced photoluminescence, with potential applications in excitonic devices like MASERs.

Contribution

It provides new insights into the photophysical behavior of picene-pentacene systems and demonstrates the impact of doping concentration on their opto-electronic properties.

Findings

Doping induces significant changes in optical response.

Efficient energy transfer from picene to pentacene observed.

Enhanced photoluminescence from pentacene in doped films.

Abstract

Here were report a study of picene nano-cristalline thin films doped with pentacene molecules. The thin films were grown by supersonic molecular beam deposition with a doping concentration that ranges between less than one molecules of pentacene every 104 picene molecules up to about one molecule of pentacene every 102 of picene. Morphology and opto-electronic properties of the films were studied as a function of the concentration of dopants. The optical response of the picene films, characterized by absorption, steady-state and time-resolved photoluminescence measurements, changes dramatically after the doping with pentacene. An efficient energy transfer from the picene host matrix to the pentacene guest molecules was observed giving rise to an intense photoluminescence coming out from pentacene. This efficient mechanism opens the possibility to exploit applications where the excitonic states of the guest component, pentacene, are of major interest such as MASER. The observed mechanism could also serve as prototypical system for the study of the photophysics of host guest systems based on different phenacenes and acenes.