Growth of perylene pigment thin films using an ionized cluster beam method and its application to photocurrent multiplication devices

A basic technique to control the growth morphology and crystal structure of thin films of a perylene pigment, N,N´ dimethylperylene-3,4:9,10-bis-dicarboximide (Me-PTC), using an ionized cluster beam (ICB) method has been developed. We deposited Me-PTC films on ITO coated glass substrates. The growth plane of Me-PTC film was found to change with deposition temperatures from (102) to (002), which corresponded to the parallel and the standing orientations of Me-PTC molecules, respectively. The optimum crystallinity was obtained at an accelerating voltage of the ICE (V_a) of 300 V. We prepared specimens using this technique to evaluate the fundamental photocurrent multiplication effect (PME) in Me-PTC. The optimum operating temperature for the PME was found to be controlled by changing V_a. A quantum efficiency of 12,500 in the PME can be attained at at room temperature, in the specimens prepared at a V, of 200 V. The ion assisted growth mechanisms of Me-PTC films, as well as the mechanism of the PME, are also discussed