Flexible Modulation of Electronic Band Structures of Wide Band Gap GaN Semiconductors Using Bioinspired, Nonbiological Helical Peptides

Abstract

Modulation of the electronic band profiles of wide band gap GaN semiconductors is achieved by the macromolecular dipole potentials exerted from ordered monolayers of synthetic, nonbiological aldehyde terminated helical peptides deposited on wet chemically oxidized GaN surfaces functionalized with aminosilanes. The selective coupling of either N‐ or C‐terminal to the amino‐terminated surface enables one to control the direction of the dipole moment, while the number of amino acids determines its magnitude. After confirming the formation of highly ordered peptide monolayers, the impact of macromolecular dipole potentials is quantified by electrochemical impedance spectroscopy. Moreover, the chronoamperometry measurements of ferrocene‐terminated peptides suggest that the transfer of electrons injected from ferrocene follows inelastic hopping, while the current responses of peptides with no ferrocene moieties are purely capacitive. Finally, the same functionalization steps are transferred to GaN/AlGaN/GaN high electron mobility transistor structures. Stable and quantitative modulation of the current–voltage characteristics of the 2D electron gas by the deposition of bioinspired peptides is a promising strategy for the macromolecular dipole engineering of GaN semiconductors.

Flat, Cα,β‐Didehydroalanine Foldamers with Ferrocene Pendants: Assessing the Role of α‐Peptide Dipolar Moments

“…A number of literature reports deal with Fc‐containing peptides, with contribution from our [15] and other laboratories [11f,13c,14,16] . In particular, self‐assembling Fc‐peptides were proposed as ideal candidates to understand charge/electron motion along polypeptide chains [17] .…”

Transformation in Low‐Frequency Noise Spectra in GaN High‐Electron‐Mobility Transistors in Nonequilibrium Conditions

“…We suggest that a description of the above-discussed physical processes may be considered also for a broad range of systems, including biosensors. [24,25]…”

Electrochemical Detection of Selective Anion Transport through Subnanopores in Liquid-Crystalline Water Treatment Membranes

“…Moreover, GaN can be alloyed with In and/or Al to vary the bandgap and realize complex semiconductor heterostructures that can be operated under aquatic environments . This makes GaN-based materials attractive toward biosensor-type applications via chemical and biochemical functionalization, such as the detection of enzymes, − lipid membranes, , peptides, and cells . Instead of applying pressures used for water treatment, we used bias potentials to “push” anions through the subnanopores.…”