High density quantum dots for powerful solar cells

TOKYO, JAPAN: The September 2014 issue of the University of Electro-Communications e-Bulletin includes research highlights on self-organized indium arsenide quantum dots for solar cells;  silicon nanophotonics; solutions to internet congestion; and humanizing robots.

Kouichi Yamaguchi is internationally recognized for his pioneering research on the fabrication and applications of 'semiconducting quantum dots' (QDs). "We exploit the 'self-organization' of semiconducting nanocrystals by the 'Stranski-Krasnov (SK) mode of crystal growth for producing ordered, highly dense, and highly uniform quantum dots," explains Yamaguchi.

"Our 'bottom-up' approach yields much better results than the conventional photolithographic or 'top-down' methods widely used for the fabrication of nano-structures."

Okuno and his colleagues fabricated silicon nanowire arrays by metal-assisted chemical etching, an approach that is simple and cost-effective. Now, Sungwan Boksuwan and co-workers at the University of Electro-Communications in Tokyo, together with scientists in Thailand, have created a new robust two-dimensional handheld micromanipulator for use in cell manipulation.

Binocular vision allows us to gauge depth. For example a dot directly ahead of the left eye will be at an angle to the right that decreases with distance. So how, ask Eiichi Mitsukura and Shunji Satoh at the University of Electro-Communications in Tokyo, can we estimate the depth of black or white paper? With no pattern or texture on the paper there should be no way of determining its contours. They turned to the computational tools used for filling in blind spots for an answer.