Presentation 10/19/10: Nanotube Composite: OPVs

Currently, photovoltaics are a new trend in the production of cheap, clean, and green energy.  There are multiple ways of producing a photovoltaic, however, one thing remains a hindrance that limits the desire for photovoltaics.  Efficiency.  A standard photovoltaic cell currently operates at an efficiency of 1-3%.  Remarkably, this is not a small amount of energy.  Unfortunately, to produce enough energy using only photovoltaics, the ratio of size to received energy is not feasible.  Very large arrays of photovoltaics are needed to produce large quantities of energy.  Therefore, intense research is being conducted to increase the efficiency of photovoltaics. 

One of the key developments is a nanotube suspension (Buckypaper) in a polymer to produce a photovoltaic at up to 15 times more efficient, and potentially up to 50 times more efficient.

Initial addition of carbon nanotubes to photovoltaics give them a new name: Organic photovoltaic devices (OPVs).  They are fabricated from thin films of organic semiconductors, such as polymers and small-molecule compounds, and are typically around 100 nm thick. Because polymer based OPVs can be made using a coating process such as spin coating or inkjet printing, they are an attractive option for inexpensively covering large areas as well as flexible plastic surfaces. A promising low cost alternative to silicon solar cells, there is a large amount of research being dedicated throughout industry and academia towards developing OPVs and increasing their power conversion efficiency.
In Short, indium tin oxide (ITO) is the primary suspended conductor in a photovoltaic.  This is the substance that conducts the solar rays into energy for use.  The problem with this material is that it is brittle and not very efficient.  It is until now the most efficient material used.  Nanotubes, though increadibly strong, allow the material to become flexible and very thin.  Of course, the efficiency is over times time more than what is currently used. 

Also, Due to the simple fabrication process, low production cost, and high efficiency, there is significant interest in dye-sensitized solar cells (DSSCs). Currently, using ITO technology, dyed cells can convert energy at a rate of 11%.  Using nanotubes, this coversion rate can be increased up to 50%.  This is even newer technology and is still under development.