Star‐shaped hybrid polymers as insulators for organic field effect transistors

Abstract

Synthesis of star‐shaped polystyrene (PS) and poly (methyl metachrylate) (PMMA) containing a polyhedral oligomeric silsesquioxane (POSS) core are fabricated by combination of atom transfer radical polymerization (ATRP) and copper (I) catalyzed azide‐alkyne cycloaddition (CuAAC) click reaction techniques. The synthetic route proceeds in two steps; firstly, clickable alkyne‐end functionalized polymeric arms and a POSS‐(N3)8 core are prepared independently by arm‐first approach using ATRP and nucleophilic substitution reaction of octa‐(3‐chloropropyl) silsesquioxane POSS‐(Cl)8 with sodium azide. Finally, the CuAAC click reactions between inorganic‐organic hybrid core POSS‐(N3)8 and alkyne functionalized PMMA and PS arms provide the targeted star‐shaped polymers. Their chemical structures and molecular characteristics are clearly confirmed by FT‐IR, 1H‐NMR, and GPC analyses. The obtained polymers are utilized as insulators for organic field effect transistors (OFETs) using perylene as an active n‐type organic semiconductor. Compared with linear PMMA and PMMA‐POSS, the POSS‐(PMMA)8 exhibited better output and transfer characteristics for the OFET device.