Organic heterostructures based on arylenevinylene oligomers deposited by MAPLE

Organic heterostructures were fabricated by matrix assisted pulsed laser evaporation (MAPLE) method using arylenevinylene oligomers based on triphenylamine (P78)/carbazole (P13) group and tris(8-hydroxyquinolinato)aluminum salt (Alq3). Optical properties of the organic multilayer structures were characterized by spectroscopic techniques: FTIR, UV-vis and photoluminescence (PL). A good transparency (over 60%) was remarked for the structures with two organic layers in the 550-800 nm range. Photoluminescence (PL) spectra proved that the emission characteristics of the materials have been preserved. I-V characteristics of (ITO/oligomer/Alq3/Al and ITO/Alq3/Al) heterostructures were symmetrically while rectifying properties of these heterostructures have not been observed. A comparison between the heterostructures made of layers with different thickness reveals that the higher current (8 × 10−6 A at 1 V) was obtained for the ITO/P78/Alq3/Al heterostructure, which is characterized by a larger thickness of the double organic layer. AFM measurements revealed a similar topography while RMS values of the reported structures depend on the organic material.