My research centers on making and understanding the physical properties of materials applicable to nanomolecular devices. The challenge lies in assembling molecules on surfaces and understanding the behavior of 1-, 2- and thin 3-dimensional (1-, 2- and thin 3-D) materials. The ultimate goal is to build surface structures with special optical and electronic properties, such as reversible electrochromic or photovoltaic behavior.
Thin 3-D layered materials are formed by stacking simpler pieces, i.e. repeated electrosynthesis of surface-bound polymers using different materials. The oxidative coupling of aromatic amine monomers leads to polymeric materials that are oxidatively reversible, semiconductive, and have intense vibrant color changes. We use an Electrochemical Quartz crystal Nanobalance (ECQN) to help determine the mechanisms of film deposition in conjunction with standard electrochemical techniques such as cyclic voltammetry and chronopotentiometry. Thin-layer Spectroelectrochemistry helps us determine what intermediates are formed in the process. We also are using Electrochemical/Electrospray/Mass Spectrometry to understand the mechanisms ion transport in and out of films, as well as for the basic understanding of electrochemical mechanisms. To date, we have developed molecule-based diodes, organic-based Schottky diodes, organic-based Schottky and Silicon-gated Thin Film Transistors (TFT). We have fabricated thin organic films in low-modulus stress sensors.
Cl4DPTD/Gel based electrochromic window
We are now developing molecular-based photovoltaics, molecular electronic circuits, solid-state reference electrodes and electrochromic windows. In all these devices a big concern is the metal/organic interface. Unlike in traditional semiconductor devices, depositing metal electrodes on organic materials requires low temperatures to prevent short circuits in nanomolecular films. Thus we are developing new electroless and electrolytic deposition techniques for electrode formation and new surface chemistries to improve adhesion between organic polymers and metal substrates. Lastly, nanoparticle-based electrochromic devices are being developed in our laboratories as an alternative to organic polymer-based electrochromics materials.
Yang, Minmin; Albrecht-Schmitt, Thomas; Cammarata, Vince; Livant, Peter; Makhanu, David S.; Sykora, Richard; Zhu, Wei. Trialkylamines More Planar at Nitrogen Than Triisopropylamine in the Solid State. J. Org. Chem. 2009, 74(7), 2671-2678.
Liang, J.; Elliot, M.C.; Cammarata, V. Polyallylammonium Ferrocyanide films for trace water detection in halogenated solvents. Electroanalysis 2009, 21(23), 2542-2548.
Jie, Yuanping; Livant, Peter; Li, Hui; Yang, Minmin; Zhu, Wei; Cammarata, Vince; Almond, Philip; Sullens, Tyler; Qin, Yu; Bakker, Eric. An Acyclic Trialkylamine Virtually Planar at Nitrogen. Some Chemical Consequences of Nitrogen Planarity. J. Org. Chem. 2010, 75(13), 4472-4479.
Li, Y., Tin, C.-C., Cammarata, V. UV-Vis. Spectroelectrochemical Study on electron blocking and trapping behaviors in conducting polymer bilayers with diphenylamine end groups. Proc. Mater. Res. Soc. 2010, 1212, 23-29.
Little, B.; Li, Y.; Cammarata, V.; Broughton, R.; Mills, G. Metallization of Kevlar Fibers with Gold, ACS Appl. Mat. & Interfaces, 2011, 3(6), 1965-1973.