by Matt Richardson @ makezine.com:
Spark has improved and expanded their product line with the Photon wi-fi development board and a pair of new wireless modules for custom circuit boards. The Photon improves on the popular Spark Core microcontroller by adding 802.11n wi-fi connectivity, SoftAP for provisioning, more memory, and a faster ARM Cortex M3 processor. Like the Core, it sits right into a standard breadboard for easy prototyping. And best of all, it can be had for $19.
Photon – A Wi-fi Microcontroller for $19 - [Link]
Research at Lawrence Berkeley National Laboratory (Berkeley Lab) has led to solar cells with record-breaking efficiency. Contrary to conventional scientific wisdom, it turns out that efficient solar cell materials are characterised by high photon emission instead of high photon absorption.
According to the researchers, external fluorescence is the key to approaching the theoretical maximum efficiency for conversion of sunlight into electricity. The maximum efficiency, called the Shockley-Queisser (S-Q) efficiency limit, is approximately 33.5% for a single p-n junction. An analysis by a member of the research team indicated that gallium arsenide is capable of approaching the SQ limit. Based on this work, Alta Devices Inc., a private company spun off by the researchers, has fabricate gallium arsenide solar cells that achieved a record conversion efficiency of 28.4%. [via]
Researchers find key to better solar cell efficiency - [Link]