Nanostructured Materials via Inorganic Chemistry 

Nanotechnology seems to be everywhere these days!  Check the newspaper, surf the web, or look to recent sci-fi books and movies.  The manipulation of matter on the nanometer scale has become a central focus from both fundamental and technological perspectives.  Unique, unpredictable and highly intriguing physical, optical, and electrical phenomena can result from the confinement of matter into nanoscale features.  As a result, the study and preparation of structures exhibiting such interesting and unusual phenomena has been termed nanotechnology or nanoscience, an exploding field still in its infancy.  Much of the driving force for building tiny devices and features on the nanoscale is their importance for existing and emerging technologies such as nanoelectronics, nano/micro-electromechanical systems (N/MEMS), sensors, molecular computing, and diagnostics which communicate directly with cells, viruses and bacteria, quantum confinement effects, and a myriad of other applications. 

Nanotechnology continues to entice the research community with the promise of exotic new materials.  These nanostructured materials offer innumerable practical applications as well as advancing an understanding of their fundamentals.  The exploration of size and structure influences on materials properties such as dielectric constant, conductivity, and luminescence has developed into a burgeoning new subdiscipline of materials science with hundreds of papers published every year.  Nowhere is this trend more prevalent than in the study of nanostructured materials.

Preparation of Metallic and Semiconductor Nanoparticles 

The term nanoparticle is generally used to indicate particles with dimensions less than 100 nanometers (one nanometer is one billionth of a meter). For comparison, a human hair is about 50,000 nm in diameter, while a smoke particle is about 1,000 nm in diameter. The smallest nanoparticles, only a few nanometers in diameter, contain only a few thousand atoms. These particles, called quantum dots, can possess properties that are entirely different from their parent materials.  In general, the properties (electrical, optical, chemical, mechanical, magnetic, etc.) of nanoparticles can be selectively controlled by engineering the size, morphology, and composition of the particles.  Reducing the size of metallic and semiconducting materials to the nanoscale can dramatically influence their structural, electrical and optical properties.  After developing materials in this near-atomic size range, engineers can combine and exploit the properties of the nanoparticle surface atoms to create new substances with enhanced or entirely different properties from their parent materials.

Electroless Noble Metal Deposition on Semiconductor Surfaces.

There is currently increased interest in patterning metallic features with reduced dimensions at the micro- and nanometer scale.  Current work in our laboratory has focused on the preparation of  thin, well-adhering nanoparticle films on semiconductor surfaces.  Deposition proceeds via galvanic displacement in the absence of HF, pH buffers, complexing agents, or external reducing agents, in contrast to prior work.  Patterning is accomplished via a variety of technologies including photolithography, microcontact printing, and dip-pen nanolithography.

Functionalization of Silicon Surfaces.

With the discovery of the photoluminescence of porous silicon by Canham in 1990, the use of ubiquitous silicon to synthesize light emitting and optoelectronic devices has become a distinct possibility.  We are interested in functionalizing the surface through a number of techniques in order to stabilize the surface through non-oxidative techniques, and prepare sensors and other micro/nanodevices.