Towards Solution Processable Single-Molecule Devices: Controlled Assembly of Carbon Nanotube Electrodes for Molecular Electronics

One of the ultimate goals in nanotechnology is the ability to produce devices based on individual molecules and nanostructures. Molecular electronics, devices that are based on single-molecules, could overcome technological limitations of current silicon-based electronic devices, and fulfill complementary technological roles.

Despite the many potential benefits envisioned for molecular-scale electronics, the strategies employed to date for device implementation suffer from various limitations, resulting in devices with poor performance, low yield and limited versatility. Principal among these limitations are the time and cost involved in fabrication, the poor control over the molecular assembly, and the lack of suitable technologies for the establishment of electrical contact between molecules and electrodes. Thus many challenges remain.

The primary goal of this project is to develop a universal approach for the production of high-throughput solution processable single-molecule nanodevices, for optoelectronic and renewable energy applications. We will achieve this applying novel methods to interface individual molecules to carbon nano-electrodes in solution, and subsequently controlling the organization of the so formed molecular junctions on surfaces for device implementation. Different classes of molecular materials both organic and inorganic, which display promising attributes, will be investigated in device configurations.

By approaching the limits of information processing, the strategy we propose has the potential to create a new generation of single-molecule multifunctional systems, and drastically reduce costs associated with device and circuit fabrication. Future technologies will require devices of this type in a variety of key areas, including ultra-high speed computation, bioelectronics, and for renewable energy applications.

We aim to develop new methods for the high-throughput production of solution processable single-molecule devices. This will enable us to comprehensively probe the properties of molecule-based electronic devices under well-controlled conditions, for logic and memory applications, as well as for renewable energy applications. Notably the methodology we will develop has the potential of functioning as a universal platform for studies at the single-molecule level.

Our work has thus the potential to generate a number of types of impact:

1) Academic Impact
The proposed research will have a wide academic impact benefiting researchers working in fundamental and applied research. Our single-molecule studies of classes of molecular materials with promising electronic attributes will contribute to the fundamental understanding of individual molecules' electrical properties in working electronic devices. This will benefit the entire organic electronics community. Additionally, the fundamental studies of charge and energy transport we will carry out in nanoscale heterostructures will benefit the inorganic community working with semiconductor nanocrystals, and the physicists studying them for renewable energy applications. Our findings will therefore be of interest to academic communities working in different fields ranging from plastic electronics and photovoltaics, to bioelectronics (for sensing).
For more details see the "Academic Beneficiaries" section.

2) Commercial and technological impact
By approaching the limits of information processing, the strategy we propose has the potential to develop a new generation of single-molecule multifunctional systems, and drastically reduce costs associated with device and circuit fabrication. Our industrial partnership will allow us to evaluate our results in the context of commercially relevant devices thus demonstrating a potential commercial utility. Future technologies will require single-molecule devices of this type in a variety of key areas, including communication devices, ultra-high speed computation, bioelectronics, and for renewable energy applications.

3) Societal Impact
The most significant and immediate societal impact of the proposed research is the training of a highly skilled versatile researcher in the form of a postdoctoral research associate (PDRA). He/she will be trained in a unique set of skills, and in a truly interdisciplinary environment, that will benefit him/her in multiple employment sectors. In particular, the PDRA will be trained in chemical reactions in aqueous solutions and organic solvents, in the self-assembly of functional molecules and nanostructures, as well as in Scanning Probe Microscopy based set-ups for the topographical and electrical characterization of functional nanostructures. Notably, the PDRA will also be trained in the use of nanofabrication techniques for the production of electronic devices, as well as in their electrical characterization. Thanks to our collaborations with academics of different fields of research and interaction with our industrial partners, the PDRA will gain experience in cutting-edge research at the interface of chemistry and materials science.

In the longer term, the proposed research will create new types of optoelectronic and renewable energy devices. This has the potential to enhance UK living standards directly through the creation of whole new types of devices and through improved performance, lowered costs and higher energy efficiencies. The UK is well placed to capitalize on progress in the field of plastic electronics in terms of job and growth creation given its position as a leader in the field both academically and industrially. By and large, the ability to fabricate solution processable single-molecule devices as intended in this proposal has the potential to enhance UK living standards and its international competitiveness.