The Advent of Mesoscopic Injection Solar Cells

Mesoscopic injection solar cells operate in an entirely different fashion than conventional solar p‐n junction devices. Mimicking the principles that natural photosynthesis has used successfully over the last 3·5 billion years in solar energy conversion, they achieve the separation of light harvesting and charge carrier transport. The semiconductors used in conventional cells assume both functions simultaneously imposing stringent demands on purity and entailing high material and production costs. The prototype of this new PV family is the dye‐sensitized solar cell (DSC). The DSC has made phenomenal progress since its discovery was announced in the scientific literature only 14 years ago.1 Conversion efficiencies of 11·3% and excellent stability have been reached rendering it a credible alternative to conventional p‐n junction photovoltaic devices. The industrial development is advancing rapidly. Several enterprises currently produce modules and flexible cells on a pilot scale and commercial manufacturing of the DSC has recently been announced. It is asserted that this type of cell is a viable contender for large‐scale future solar energy conversion systems on the bases of cost, efficiency, stability and availability, as well as environmental compatibility.