No abstract

Synthetic melanin based metal–insulator–semiconductor devices are fabricated for the first time thanks to silicon surface wettability modification by using dielectric barrier discharge plasma. Ambipolar charge trapping in air and ion drift mechanisms under vacuum are identified by capacitance–voltage hysteresis loops. These results aim to foresee the possible integration of synthetic melanin layers as a novel capacitor in organic polymer based devices.

Eumelanin-type biopolymers have attracted growing interest in the quest for soft bioinspired functional materials for application in organoelectronics. Recently, a metal-insulator-semiconductor device with a good quality interface was produced by spin coating of a com. synthetic eumelanin-like material on a dry plasma-modified silicon surface. As a proof-of-concept step toward the design and implementation of next-generation eumelanin-inspired devices, we report herein an expedient chem. strategy to bestow n-type performance to polydopamine, a highly popular eumelanin-related biopolymer with intrinsic semiconductor behavior, and to tune its elec. properties. The strategy relies on aerial co-oxidn. of dopamine with suitable arom. amines, e.g. 3-aminotyrosine or p-phenylenediamine, leading to good quality black polymeric films. Capacitance-voltage expts. on poly(dopamine/3-aminotyrosine) and poly(dopamine/p-phenylenediamine)-based metal insulator semiconductor devices on p-Si indicated a significant increase in flat band voltage with respect to polydopamine and previous synthetic eumelanin-based diodes. Variations of the flat band voltage under vacuum were obsd. for each device. These results point to polydopamine as a versatile eumelanin-type water-dependent semiconductor platform amenable to fine tuning of its electronic properties through incorporation of π-conjugating arom. amines to tailor functionality

No abstract

No abstract