Nanotechnology and Design

Hot Electrons and Photovoltaics The term hot electrons/carriers refer to electrons that have gained very high kinetic energy after being accelerated by a strong electric field in areas of high field intensities within a semiconductor device. Hot carriers can get stuck in unwanted areas of a device and cause degradation or instability.   Photovoltaics is the direct conversion of light into electricity at the atomic level. A typical photovoltaic system employs solar panels, each comprising a number of solar cells, which generate electrical power. However the efficiency of photovoltaic materials is compromised by their inability to capture all the energy absorbed when hot electrons form. Lead researcher Isabell Thomann of Rice University says “Hot electrons have the potential to drive very useful chemical reactions, but they decay very rapidly, and people have struggled to harness their energy.” In today’s best photovoltaic solar panels, most of the energy losses are the r...

Fluid Wettability This week we learned about the wettability of different surfaces. The experiment we had in class dealt with various ways we changed the exterior of a copper plate to make it into a super hydrophobic or super hydrophilic surface. While researching I came across an article that described a new material that switches from super hydrophobic to super hydrophilic in an instant. Copper was deposited onto a surface by a process called electrodeposition which makes it grow like an array of Christmas trees. Electrodeposition i.e. electroplating is a process that uses electric current to reduce dissolved metal cations so that they form a coherent metal coating on a conductive material. The scientists used copper because it is cheap and abundant but the team believes that the electrochemical manipulation of other metals, metal oxides, and mixed oxides may yield similar results.   They then ran a voltage through this new material and saw that water dropl...

Programmable Matter This week we had an experiment based on photolithography where we made circuit boards with this method. Photolithography is a process used to pattern parts of a thin film using light to transfer a geometric pattern from a photoresist onto the substrate. I decided to look further into lithography in general and was able to find a branch of nanotechnology concerning nanolithography. It’s the application of fabricating nanometer-scale structures with different approaches being optical, electron-beam, nanoimprint, multiphoton, scanning probe, and other lithography techniques.   All of these procedures are capable of producing patterns with at least one lateral dimension between 1 and 100 nm.   Researching this particular method led me to reading about programmable matter which is matter that has the ability to change its physical properties in a programmable fashion, based upon user input or autonomous sensing.   It seems, in t...