EES Blog

Jeffrey Grossman and coworkers communication on 3D solar energy harvesting has been highlighted in ScienceDaily. The MIT researchers modelled and built three-dimensional photovoltaic arrays which are able to provide more energy, more consistently throughout a day. The work was also highlighted in our recent blog article.

Read this HOT communication in full today:

Solar energy generation in three dimensions
Marco Bernardi, Nicola Ferralis, Jin H. Wan, Rachelle Villalon and Jeffrey C. Grossman
Energy Environ. Sci., 2012, DOI: 10.1039/C2EE21170J

US researchers have come up with an explanation for their recent results that show that introducing piezoelectric semiconductor nanowires into solar cells improves their efficiency.

Piezoelectricity is the charge created when certain materials are placed under stress, where compressing or stretching the substance generates electricity. Piezoelectric materials have been used as sensors in cars, as energy scavengers and also as ignition sources in electric lighters. Researchers across the world are working on improving the efficiency of photovoltaic devices, but until recently hadn’t thought of harnessing piezo-potential to do so.

Schematic and energy band diagram of (a) a general nanowire piezoelectric solar cell fabricated using a p-n junction structure. Schematics and energy band diagram of the piezoelectric solar cells under (b) compressive strain and (c) tensile strain, where the polarity and magnitude of the piezopotential can effectively control the carrier generation, separation and transport characteristics. The colour code represents the distribution of the piezopotential at the n-type semiconductor

Interested to know more? Read the full article in Chemistry World here…

Read the Communication from EES: 

Piezo-phototronics effect on nano/microwire solar cells
Yan Zhang ,  Ya Yang and Zhong Lin Wang
Energy Environ. Sci., 2012, Advance Article
DOI: 10.1039/C2EE00057A

Researchers based in Australia have found a way to convert more of the energy from the sun into useful energy, without massively increasing the cost of the process.

Currently photons with energy below a certain threshold are not picked up by most solar cells, but by combining two photons to make a single photon of  higher energy (upconversion) more of the incoming radiation can be utilized.

Schmidt, Lips and co-workers describe a hydrogenated amorphous silicon (a-Si:H) solar cell backed by  a layer of palladium porphyrin capable of upconverting photons, which are then able to be radiated back into the a-Si:H layer and converted to useful energy.

Read this HOT paper in full today:

Improving the light-harvesting of amorphous silicon solar cells with photochemical upconversion
Yuen Yap Cheng, Burkhard Fückel, Rowan W. MacQueen, Tony Khoury, Raphaël G. C. R. Clady, Tim F. Schulze, N. J. Ekins-Daukes, Maxwell J. Crossley, Bernd Stannowski, Klaus Lips and Timothy W. Schmidt
Energy Environ. Sci., 2012, DOI: 10.1039/C2EE21136J

Cost is a major drawback in the current silicon wafer technology used for photovoltaic cells. In this HOT communication Charles Teplin and co-workers report a proof-of concept solar cell using a thin film of crystal silicon grown on an inexpensive CaF₂ “seed” layer.

Read the full details of this exciting Communication:

Biaxially-textured photovoltaic film crystal silicon on ion beam assisted deposition CaF₂ seed layers on glass
James R. Groves , Joel B. Li , Bruce M. Clemens , Vincenzo LaSalvia , Falah Hasoon , Howard M. Branz and Charles W. Teplin
Energy Environ. Sci., 2012, DOI: 10.1039/C2EE21097E