The analytical and Surface Chemistry (ASC) Program of the Division of Chemistry supports the research project of Prof. Amy walker of the University of Texas at Dallas. Prof. Walker and her students will develop methods for chemically selective deposition of metals on organic thin films and apply these methods to construct complex multilayer structures. The reliable production of stable metallic contacts to organic thin films is critical in many technologies, including polymer light emitting diodes (PLEDs) and molecular and organic electronics. Fundamental to this goal is a quantitative understanding of the interactions of deposited metals with the terminal functional groups in organic films. Prof. Walker and her students will define and explore these critical interactions using self-assembled monolayers (SAMs) as model systems. The study will focus on the deposition of aluminum, copper, nickel, platinum, palladium and gold. These metals all have important applications as contacts in molecular-, organic- and magneto- electronic devices. The study will provide excellent training opportunities to students who wish to train in the cutting edge research of molecular electronics.
The reliable production of stable metallic and semiconducting layers to organic thin films is critical in many technologies, including polymer light emitting diodes (PLEDs), energy harvesting, and molecular and organic electronics. Fundamental to this goal is a quantitative understanding of the interactions of deposited metals and semiconductors with the terminal functional groups in organic films. Prof. Amy Walker and her group have developed methods for the chemically selective deposition of metals and semiconductors on organic films using self-assembled monolayers (SAMs) as model systems. The study focused on the deposition of aluminum, copper, nickel, zinc oxide, zinc sulfide and lead sulfide. These metals and semiconductors all have important applications as contacts in molecular-, organic- and magneto- electronic devices, and the semiconductors have applications in energy harvesting devices. In their investigations Prof. Walker and her group developed a room temperature photo-activated chemical vapor deposition process for aluminum, electroless deposition methods for the selective deposition of copper and nickel on organic films, selective atomic layer deposition processes for zinc sulfide and zinc oxide, and chemical bath deposition methods for the deposition of lead sulfide and zinc oxide. These studies show that the deposition selectivity and deposit morphology are controlled by the choice of the deposition method as well as the organic surface and the experimental conditions. For example, using chemical bath deposition can be deposited as nanorods, nanoflowers and even "nanorockets". In contrast, zinc oxide is deposited as a smooth layer using atomic layer deposition. Finally the Walker group has developed a promising new method, electroless nanowire deposition on micropatterned substrates (ENDOM), by which to direct the in situ growth and placement of nanowires. This technique has the potential to greatly simplify fabrication methods for the development of new nanoelectronic devices and sensors. During the past 4 years, one posdoctoral scholar (a woman who is also disabled), nine graduate students (including 4 women and one from an under represented group student), five undergraduates (four women, one from an under represented group) and one high school student (also a woman) have participated in our group's research program. Of the undergraduates who have graduated or in their senior year, three have gone or are planning to go to graduate school. One undergraduate has entered the work place and works for as a scientist in the petrochemical industry. The project has substantially developed the skills and expertise of the primary project personnel by providing training in a wide variety of laboratory techniques, improved their communication skills, and has given students experience in collaborating with companies. Finally, the students have been exposed to new, fast moving interdisciplinary research areas including organic electronics and sensing. Prof. Walker is active in both curriculum development and efforts to improve student retention. She is the chair of a committee overseeing a multidisciplinary minor in Nano Science and Technology. As part of the program she has developed new curricula for classes and revised the overall minor curriculum introducing new classes. In her classes Prof. Walker uses examples from her own research to illustrate the growing fields of nano science and technology. Prof. Walker leads a Research Experience for Undergraduates program in surface engineering. The goal of this program is to provide research opportunities to students from schools with limited opportunities, women and under-represented groups. As well as leading the program Prof. Walker hosts REU participants and students from the Texas LSAMP program in her laboratories, and helps advise these students on going to graduate school.
