title: Molecular fluorescence from H2TBP porphyrin film on Ag substrate excited by tunneling electrons.
abstract: Molecular fluorescence from H(2)TBP porphyrin (H(2)TBPP) films on Ag substrate is excited by a scanning tunneling microscope (STM) at ambient conditions. The molecular films are prepared by spin-casting method. The thickness of films can be controlled by the times of dropping H(2)TBPP solution. Molecular fluorescence of as-above prepared H(2)TBPP films with 4-14nm thickness at both polarities of applied bias voltage are well defined in good matching with its photoluminescence spectrum, which suggests the same decay channel associated with the HOMO-LUMO radiative transitions similar to H(2)TBPP/Au. The thickness dependence of light emission intensity of molecular fluorescence has been studied. The results show that for thicker film, molecular fluoresceence tends to be much stronger due to the effective decoupling of the emitter from the metal substrate.
authors: The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan. hwliu31@sanken.osaka-u.ac.jp
authors: Hongwen
authors: H
authors: Liu
authors: Ryusuke
authors: R
authors: Nishitani
authors: Yutaka
authors: Y
authors: Ie
authors: Koichi
authors: K
authors: Sudoh
authors: Marek
authors: M
authors: Nowicki
authors: Tatsuo
authors: T
authors: Yoshinobu
authors: Yoshio
authors: Y
authors: Aso
authors: Hiroshi
authors: H
authors: Iwasaki