Mesoscopic solar cells are one of the most promising photovoltaic technologies among third generation photovoltaics due to their low cost and high efficiency. The morphology of wide-band semiconductors, sensitized with molecular or nanosized light harvesters, used as electron collectors contribute substantially to the device performance. Recent developments in the use of organic-inorganic layer structured perovskites as light absorbers and as electron or hole transport materials allows reduction in the thickness of photoanodes to the submicron level and have raised the power conversion efficiency of solid state mesoscopic solar cells above the 10% level.
We thank Prof. Michael Gratzel for fruitful discussions. Financial support from the Swiss National Science Foundation is gratefully acknowledged. The Research was partially supported by the King Abdullah University of Science and Technology (KAUST, Award No. KUS-C1-015-21).