Imaging and spectromicroscopy of photocarrier electron dynamics in C60 fullerene thin films

We have employed a two-photon photoelectron emissionmicroscopy (2P-PEEM) to observe the photocarrier electrondynamics in an organic thin film of fullerene (C60) formed on a highly oriented pyrolytic graphite with aspatial resolution of ca. 135  nm. In this approach, photocarrier electrons in C60 single-layer islandsgenerated by the first pumpphoton are detected by the second probephoton. These spectromicroscopic observations conducted over a 100  × 100 nm2 region of C60 islands consistently reproduced the macroscopic two-photonphotoemission spectrum of fully covered C60monolayer film, where the energy of photocarrier electron in the islands was +0.9  eV relative to the Fermi level.Time-resolved 2P-PEEM revealed that the photocarrier electron decayed from the monolayered C60 islands into the substrate with a time constant of 470  ± 30 fs.

Source: Applied Physics Letters - November 15, 2016 Category: Physics Authors: Masahiro Shibuta, Kana Yamagiwa, Toyoaki Eguchi and Atsushi Nakajima Source Type: research