NanoTechnology: Materials, Processes & Devices

The intrinsic advantages of III-V semiconductors for solar cells have been hobbled by the lack of low-cost substrates and processes, which has thus far limited market success of III-V solar cells. Here at Berkeley we are exploring a non-traditional approach which addresses these drawbacks. High optical quality polycrystalline InP films have been grown on non-epitaxial molybdenum substrates. Remarkably, these films with micron-sized grains have similar photoluminescence qualities as single- crystalline InP, and show great promise for high-efficiency, low-cost solar cells....

Solar hydrogen production by photoelectrochemical water splitting holds great promise for efficient solar energy harvesting and storage. To achieve spontaneous water splitting, developing efficient photoelectrodes with both high photovoltage and high photocurrent is highly desirable. However, current studied photocathodes such as p-Si, p-Cu2O and p-GaP have photovoltage lower than half of 1.23 V, the minimum voltage required for water splitting. To overcome these challenges, we are currently developing a photocathode using amorphous Si thin film with TiO2 encapsulation layer for...

As energy demands continue to rise, it becomes imperative to develop efficient energy storage devices with high energy and power density. At the same time, the space inside devices continues to shrink, making energy storage devices which possess not only high energy/power density, but also an adjustable shape to fit into various form factors an ideal solution. Energy storage devices made from flexible electrodes are attractive in a roll-up or surface-conformed format to minimize space usage. A mechanically flexible CNT supercapacitor electrode is demonstrated, as well as a lithium-...

Early stage cancer diagnosis may mean the difference between a successful or an ineffective treatment. Therefore, development of methods that allow the detection of premature signatures of cancer are necessary. Mature microRNAs are short non-coding RNAs strands (~18-21 nt) involved in gene regulation of eukaryotic cells. In cancer cells some miRNAs appear over or under expressed, and serve as a markers to signal the presence of these malignancies. MicroRNAs, however, are present in very low concentrations, thus sensitive and multiplexed methods that detect specific miRNAs are needed...