This month a very interesting article in the Journal of Physical Chemistry Letters has been published by Henry Snaith, one of the instigators of the new Perovskite Solar cells that have already consolidated as one of the most promising and feasible low-cost photovoltaic technologies.
(Perovskite solar cells from Swansea Univeristy. Picture by Matt Carnie)
In the article he describes the evolution from the initial liquid dye-sensitised solar cell, to the solid state device using OMeTAD, then the extremely thin absorber (ETA) approach and finally the Perovskite solar cell or also known as Meso-Superstructured Solar Cell (MSSC).
One of the most impressive characteristics of the perovskites is that it groups all the three essential mechanisms for the photovoltaic conversion of energy into a single material, i. e. the perovskite is able to absorb the light, accumulate the separated carriers and transport both electrons and holes to the external contacts.
The most recent improvements in efficiency already reach 15% efficiency, using different configurations, a planar thin-film device (reported by Liu et. al.) and a nanostructured approach (reported by Burschka et al.). Snaith also remarks in the article that efficiencies of 20% or 25% could be also possible in the near future, reaching the most efficient current photovoltaic technologies.