Anomalous photoelectric emission from Ag on zinc-phthalocyanine film

作者：Tanaka Senku^*; Otani Tomohiro; Fukuzawa Ken; Ogawa Koji; Azuma Junpei; Yamamoto Isamu; Takahashi Kazutoshi; Kamada Masao; Hiromitsu Ichiro

来源：Applied Physics Letters, 2014, 104(19): 193304.

DOI：10.1063/1.4876956

Photoelectric emission from organic and metal thin films is generally observed with irradiation of photon energy larger than 4 eV. In this paper, however, we report photoelectric emission from Ag on a zinc-phthalocyanine (ZnPc) layer at a photon energy of 3.4 eV. The threshold energy for this photoelectric emission is much smaller than the work function of Ag estimated by conventional photoelectron spectroscopy. The photoelectric emission by low-energy photons is significant for Ag thicknesses of less than 1 nm. Photoelectron spectroscopy and morphological study of the Ag/ZnPc suggest that the anomalous photoelectric emission from the Ag surface is caused by a vacuum level shift at the Ag/ZnPc interface and by surface plasmons of the Ag nanoparticles.

• 出版日期2014-5-12