Lignin: a biobased dielectric polymer for Organic Field Effect Transistors (OFETs)

Lignin is a biopolymer, recovered as a waste product of industrial pulping processes of lignocellulosic biomass. Lignin displays a complex structure, poor solubility in common solvents, broad distribution of molecular weight, and properties that depend on natural origin and isolation procedure [1]. This makes the lignin valorization a challenging point for chemists and materials scientists, especially in device fabrication where materials with regular and definite molecular structures are required [2]. In this communication, we present the structural and chemical-physical characterization of two kraft lignins, named L1 and L2, and we describe which structural characteristics will affect lignin efficiency in serving as an excellent gate dielectric polymer for OFET devices. Our promising results demonstrate the effectiveness of L1 and L2 as gate dielectric layers in pentacene or C60-based bottom gate top contacts OFET devices [3]. In addition, we present the solvent fractionation of L1 and L2 by Soxhlet or Kumagawa methods, supporting a deeper characterization of their chemical structures