First All-Carbon Solar Cell

Few weeks ago, the first solar cell with all its components made of carbon-based materials has been published in ACS Nano journal. The work has been developed by researchers in Standford University (USA), University of Rochester (USA) and Nankai University (China). Previously a solar cell with their active layer made using carbon materials was reported, but Zhenan Bao and her colleagues have fabricated this new cell with even their electrodes based on carbon as well. They replaced the silver and ITO (Indium tin oxide) used in conventional electrodes with graphene and single-walled carbon nanotubes exhibiting extraordinary electrical conductivity and light-absorption properties. For the active layer, the scientists used carbon nanotubes and C60 derivatives. 

 

The all-carbon cell absorbs near-infrared wavelengths of light, leading to a laboratory efficiency of less than 1 percent (0.0041 %). However, as the inventors says, there is still plenty of room for improvement that could lead in the future to reach >1 % efficiencies. The main contribution of this new cell is its potential as an alternative to the expensive materials used in photovoltaic devices today, since the thin film prototype is made of carbon materials that can be coated from solution, are low-cost and Earth-abundant. 

Impedance Spectroscopy for Energy Conversion Devices

Impedance Spectroscopy (IS) has become a major tool for the analysis and understanding of energy conversion devices. Since the appearance of nanostructured and nanoporous materials as well as organic and molecular conductors, new models have been developed in the framework of this powerful technique to understand properly the new features observed in these novel materials. The main advantage of the technique is the possibility in most of the cases of separating all the physical processes that take place in the device or material, being able to provide in a single measurement most of the physical parameters needed to characterise the system. However, in order to properly extract the physical information from this technique an in depth knowledge and skilled interpretation is required, what makes it hard to apply to many scientists.


The Photovoltaic and Optoelectronic Devices (POD) group at Universitat Jaume I in Spain are the pioneers in the development of this knowledge and expertise and have successfully applied IS analysis to a wide range of energy conversion devices, such as Dye-Sensitised Solar Cells, Organic Solar Cells, Quantum Dots Solar Cells and more recently Photoelectrochemical Water Splitting devices. Prof. Juan Bisquert, the POD group leader, has shared in his blog a very interesting presentation covering the use of IS in all these devices mentioned. It can be accessed directly above or by clicking here.