Photoelectric cells of copper phtalocyanine thin films utilizing surface plasmon excitation

Abstract

Short-circuit photocurrent (I/sub sc/) due to surface plasmon (SP) excitation has been investigated for the photoelectric cells using copper phtalocyanine (CuPc). The CuPc molecule exhibits p-type conduction, and the Schottky and Ohmic contacts are obtained at the interfaces between CuPc and Al thin films and between CuPc and Ag thin films, respectively. Since the Schottky diodes show the photoelectric effects, the Schottky photoelectric cells have been constructed. The cells had a prism/Al/CuPc/Ag structure of the Kretschmann configuration in the attenuated total reflection (ATR) method. SP has been resonantly excited at the interface between Ag and air. The ATR and the I/sub sc/ properties have been simultaneously measured as a function of the incident angles of the laser beams. The peaks of the Isc have corresponded to the resonant angles of the ATR curves. The electric fields and optical absorptions in the cells have been also calculated using the complex dielectric constants and the film thicknesses obtained from the ATR measurements. The calculated absorptions in the CuPc thin film as a function of the incident angles have corresponded to the results of I/sub sc/. It has been estimated that the Isc could be enhanced by the excitations of SP in the ATR configuration.