Polarity‐Controlled Attachment of Cytochrome C for High‐Performance Cytochrome C/Graphene van der Waals Heterojunction Photodetectors

Abstract

Biomolecule/graphene van der Waals heterojunction provides a generic platform for designing high-performance, flexible, and scalable optoelectronics. A key challenge is, in controllable attachment, the biomolecules to form a desired interfacial electronic structure for a high-efficiency optoelectronic process of photoabsorption, exciton dissociation into photocarriers, carrier transfer, and transport. Here, it is shown that a polarity-controlled attachment of the Cytochrome c (Cyt c) biomolecules can be achieved on the channel of graphene field effect transistors (GFET). High-efficiency charge transfer across the formed Cyt c/graphene interface is demonstrated when Cyt c attaches with positively charged side to GFET as predicted by molecular dynamics simulation and confirmed experimentally. This Cyt c/ GFET van der Waals heterojunction nanohybrid photodetector exhibits a spectral photoresponsivity resembling the absorption spectrum of the Cyt c, confirming the role of Cty c as the photosensitizer in the device. The high visible photoresponsivity up to 7.57 × 10 4 A W −1 can be attributed to the high photoconductive gain in exceeding 10 5 facilitated by the high carrier mobility in graphene. This result therefore demonstrates a viable approach in synthesis of the biomolecule/graphene van der Waals heterojunction optoelectronics using polarity-controlled biomolecule attachment, which can be expanded for on-chip printing of high-performance molecular optoelectronics.

Lateral Graphene p–n Junctions Realized by Nanoscale Bipolar Doping Using Surface Electric Dipoles and Self‐Organized Molecular Anions

“…Lateral Graphene p–n Junction Devices Fabrication and Characterization : Large‐scale single‐layer graphene of typically 0.5 × 1.0 cm 2 in dimension was synthesized in a chemical vapor deposition (CVD) system on commercial copper foils (Alfa Aesar) . Subsequently, CVD graphene was transferred onto the PLZT film, and GFETs were fabricated using a similar method reported in the previous works.…”

2D–Organic Hybrid Heterostructures for Optoelectronic Applications

“…Molecular dynamics simulations and experimental characterizations revealed effective exciton dissociations and high‐efficiency charge transfer across the Cyt c/graphene interface. A photoresponsivity of up to 7.57 × 10 4 A W −1 at 410 nm was achieved (Figure i) . Use of a wider variety of molecules can further improve the performance of PDs based on 2D–biomolecule hybrid structures.…”

“…h) Cyt c–graphene heterostructure with i) spectrally resolved photoresponsivity. h,i) Reproduced with permission . Copyright 2018, Wiley‐VCH.…”

“…Furthermore, a mixed‐dye organic layer was utilized as a light‐absorbing layer over a broad wavelength range; the resulting PD showed a full‐color optical bandwidth photoresponse across the visible spectrum (Figure g) . Another type of high‐performance graphene–organic phototransistor was developed via polarity‐controlled attachment of a cytochrome c (Cyt c) biomolecule (Figure h) . Molecular dynamics simulations and experimental characterizations revealed effective exciton dissociations and high‐efficiency charge transfer across the Cyt c/graphene interface.…”

Large photoelectric-gating effect of two-dimensional van-der-Waals organic/tungsten diselenide heterointerface

“…The rise and decay time of photocurrent are 120 and 80 ms when V g = 0 V, about 1-2 orders of magnitude faster than that (rise time: 2 s, decay time: 25 s) when V g = −60 V, which indicates that the electrical gating can effectively modulate the charge trapping process, and more electrons are accumulated when a negative V g is applied. 44,45 Electric-gating switchable photodetectors As a result of electric-gating modulated charge trapping process (Fig. 4a, b), the photocurrent response of p-MSB-1/WSe 2 can be switched "ON" and "OFF", or turned up by applying different V g .…”