The title would be quite accurate even if we said "Soft chemistry based organic photovoltaics".
In a solar cell, the electron-hole pair generated when light is incident on the junction needs to be efficiently (i) separated (in space), to ensure that they do not recombine, and (ii) collected at the electrodes. We use a low temperature approach to make a large array of nano-needles of a material called ZnO. This material is known to be a good collector of electrons. The large array of ZnO nanoneedles means that we have a large surface area over which electrons can be effectively collected. We achieve excellent current densities in this device, but sadly observe low voltage supplies coming off the device (technically this device parameter is called "Open circuit voltage"). We are chugging our way through, and sooner than you realize, we may have a cool device in hand. So do check back with us, if you happen to bump into this story!
By the by, this story became an invited contribution in IEEE Photovoltaics (Boston conference, July 2013). Kudos to Arun and his team who made this possible! Please click here to see the poster Arun presented when he was away, sharing this story with materials scientists in Boston.
