Co-deposition of Phthalocyanines and Fullerene by SuMBE: Characterization and Prototype Devices

Supersonic molecular beams epitaxy (SuMBE) have been used for the co-deposition of organic thin films and the development of prototype devices.We took advantage of the unique features of SuMBE, including the ability to ''tune'' the initial state (kinetic energy, momentum, flux, etc.) of the molecules during the deposition process, to control the growth of doped organic materials and distributed interfaces in view of the realizations of electro-optic devices with improved performance. SuMBE gives in fact thin films with a high degree of crystallinity that can be functionalized in situ. We achieved a very good control on the co-deposition of a p-type semiconductor (metal phthalocyanines (MPc)) with an n-type semiconductor (fullerene), without phase segregation between the two compounds and with a high control on the deposition parameters. The optical characterization of the co-deposited films shows clearly the charge transfer signature. Prototype solar cells produced by SuMBE show a good photovoltaic response with high degree of stability and reproducibility.