How band tail recombination influences the open‐circuit voltage of solar cells

The power conversion efficiency of solar cells strongly depends on the open-circuit voltage which, in turn, recombination activity within device. A possible source detrimental charge carrier is band tails. An empirical linear relationship between loss and Urbach energy tails has been shown past. Here we discuss how influence radiative nonradiative bulk absorber. First, show through photoluminescence that can be willfully tuned state-of-the-art thin-film Cu (In,Ga)Se2 (CIGSe) absorbers a 20% level beyond incorporation alkali atoms. In second part, compare our CIGSe results to published from other cell technologies. This comparison reveals CIGS follow previously described trend: an increase with decreasing Finally, model tail states losses: Radiative increased because carriers thermalize into free bands Shockley–Read–Hall states. experimental data shows even worse than SRH predicted by model. Our thus suggest act as one main remaining limitations majority cells.