Figure 1.

Power conversion efficiency in the Shockley–Queisser model (solid line) as a function of band gap compared with experimentally achieved values of efficiency in different photovoltaic technologies. Data are taken from the NREL efficiency chart [4], the efficiency tables [1] and some individual papers [5,6] in cases where the record in the references above did not have associated data that allowed estimating the band gap of this particular compound or molecular blend. In case of the perovskite solar cells, the current efficiency record according to the NREL efficiency chart is 23.7%. The best certified and published data from [5] is 22.6%. (Online version in colour.)