Professor Shin,
Thank you for your interest in my work.

Q: What was the relevance of hematite in this study?
A: Biomineralization systems such as the tooth of the chiton mollusk are known to form magnetite from a hydrated iron (III) oxide precursor (ferrihydrite). This observation coupled with the well-established solution syntheses of iron oxides reported by the colloid community lead us to believe that iron (III) oxide was suitable compound to use for these first studies of bio-inspired growth of transition metal oxides in a hydrogel. The goal is to explore this system for potential applications, but also to use this system to inform the design of hydrogel-based growth systems for other transition metal oxide systems that are currently being studied for such applications (e.g., ZnO, TiO2).

Q: Also, how do you envision your materials to be incorporated into a device? Can you give a real-word example?
A: As an excitonic solar cell material, the goal is to use these materials in a bulk heterojunction configuration. Assuming we can form a nanocomposite with good thermal and electrical properties, device fabrication could be undertaken. Currently, a great deal of research effort is aimed at forming bulk heterojunction structures based on ZnO as the electron acceptor material. These materials are assembled on ITO substrates for pairing with a good donor material (e.g., TiO2). Ultimately the success of this approach relies on the donor material having intimate contact with the acceptor, and having structural features that facilitate exciton dissociation, all the while maintaining single crystal character. The a-Fe2O3 phase formed in this study has n-type semiconducting properties and would thus be considered as the electron acceptor material for such a device. It may be possible to grow appropriate donor (p-type) oxides on top of the acceptor (n-type) layer using the bio-inspired crystal growth techniques that I am currently developing.
Thank you!!