Synthesis, characterization and investigation of the new graft copolymers as interfacial layer in diodes

In this study, polymeric linoleic acid (PLina) and polymeric linolenic acid (PLinl) peroxide were obtained by auto-oxidation of linoleic acid (Lina) and linolenic acid (Linl). The auto-oxidation of Lina and Linl were performed at room temperature under daylight and air oxygen. Obtained polymeric fatty acids were used free radical polymerization of tert-butyl acrylate (tBA) monomer to synthesize PLina-g-PtBA ve PLinl-g-PtBA graft copolymers. Also, this polymeric fatty acids both having the peroxide groups and carboxylic acid groups were used in the one-pot method (free radical polymerization and ring opening polymerization combination of both using). So, triblock graft copolymers were synthesized. In the one-pot method, while the peroxide groups of the polymeric fatty acids were polymerized the tert-butyl acrylate via free radical polymerization, carboxylic acid groups of the fatty acids were polymerized the ε-caprolactone (or D,L-lactide) via ring opening polymerization at the same time. Thus, the PLina-g-PCL-g-PtBA, PLina-g-PLA-g-PtBA and PLinl-g-PCL-g-PtBA triblock graft copolymers were synthesized. The principal parameters such as monomer concentration and initiator concentration that affect polymerization reaction of two and triblock graft copolymers were investigated. The obtained graft copolymers were characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Also, metal/semiconductor Schottky diodes using in the production of interfacial PLilPCLPtBA-4 graft copolymer insulator layer was investigated. For this, interfacial PLilPCLPtBA graft copolymer layer is formed which was coated onto the Si single crystal piece using electrospining method. Morphological properties of the polymeric surface were analyzed by using area effective scanning electron microscope gun (FEG-SEM). In the last step, Au/n-Si (metal–semiconductor [MS]) and Au/PLilPCLPtBA-4/n-Si (MPS) diodes' I–V measurements were realized using a Keithley 2400 source-meter at room temperature and in the dark.