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Posts Tagged ‘solar cells’

Research Review – Tues. June 24 2014

Tuesday, June 24th, 2014

Germany is making research headlines this week, with NeuLand research reducing energy losses and the University of Kaiserslautern’s work into ‘smart glass’ for the next generation of smartphone cameras. Still with smartphones, IDC believes that this market will boost connected device growth to double digit levels. Finally, researchers at Rice University, have etched silicon to allow 99% of sunlight to reach cells.

German partners, including Infineon, in the NeuLand project, funded by the German Federal Ministry of Education and Research, have developed integrated components and electronic circuits to reduce energy loss in circuits by 35%.
Energy losses are halved by using SiC (silicon carbide) and GaN-on-SiC (gallium nitride on silicon). Today Infineon already uses the material SiC in its JFETs and diodes for the 600V to 1700V voltage class. These power semiconductors are primarily used in switched-mode power supplies for PCs or televisions and in motor drives. In the future they may also gain major significance for solar inverters. In future, also solar inverters could considerably profit.
NeuLand is an abbreviation from the German for “Innovative power devices with high-energy efficiency and cost effectiveness based on wide bandgap compound semiconductors”.

A small, low-powered camera component made from a “smart glass” material has been created by a group of researchers in Germany with the hope of inspiring the next generation of smartphone cameras.
A micro-iris smart glass material is the hope for the next-generation of smartphone cameras. It is, says researchers, from the University of Kaiserslautern, Germany, an electro-chemical equivalent to the bulky, mechanical blades in cameras to create the aperture stop, which controls the light which enters.
Using an electrochromic material, or “smart glass”, the transparent material is transformed into an opaque material when a small electrical voltage is applied to it.
In the study, the researchers fabricated a micro-iris using two glass substrates sandwiched together, and with each one carrying a thin film of electrochromic material, called PEDOT, on an underlying transparent electrode. The micro-iris was 55 µm thick and could be switched into an opaque state using a current of 20 µA with a voltage of 1.5 V. The micro-iris exhibited a memory effect and did not require a continuous current to maintain the opaque state, so its power consumption remained very small.

Researchers at Rice University have found a simple way to etch nanoscale spikes into silicon that allows more than 99% of sunlight to reach the cells’ active elements, where it can be turned into electricity.
The research by Andrew Barron and graduate student and lead author Yen-Tien Lu have replaced a two-step process that involved metal deposition and electroless chemical etching with a single step that works at room temperature.
The mix of copper nitrate, phosphorous acid, hydrogen fluoride and water is applied to a silicon wafer, and the phosphorous acid reduces the copper ions to copper nanoparticles. The nanoparticles attract electrons from the silicon wafer’s surface, oxidizing it and allowing hydrogen fluoride to burn inverted pyramid-shaped nanopores into the silicon.
Following fine-tuning, the black silicon layer with pores down to 590nm allows through over 99% of light, whereas a clean, un-etched silicon wafer reflects nearly 100% of light.

Smartphones are expected to lead double-digit growth of smart connected devices, which IDC predicts will grow 15.6% year over year in 2014, reaching close to 1.8billion devices.
Growth of smartphones will lead that of PCs and tablets. By 2018, the analyst estimates shipments will grow to 2.4billion units.
IDC is forecasting strong double-digit growth in the low-cost Android smartphone segment that is driving much of the growth in emerging countries such as China, India, and Brazil. Mature markets such as the United States and Western Europe are slowing to single-digit growth rates.
The influx of inexpensive phones will drive the smart connected device segment growth, with sub-$200 band increasing from 33% of total shipments in 2013 to greater than 43% in 2018. Devices that cost more than $500 are forecast to shrink from 33% of total device shipments to 21.1%.”