A mixed-cation lead mixed-halide perovskite absorber for tandem solar cells

Metal halide perovskite photovoltaic cells could potentially boost the efficiency of commercial silicon photovoltaic modules from ∼20 toward 30% when used in tandem architectures. An optimum perovskite cell optical band gap of ~1.75 electron volts (eV) can be achieved by varying halide composition, but to date, such materials have had poor photostability and thermal stability. Here we present a highly crystalline and compositionally photostable material, [HC(NH2)2](0.83)Cs(0.17)Pb(I(0.6)Br(0.4))3, with an optical band gap of ~1.74 eV, and we fabricated perovskite cells that reached open-circuit voltages of 1.2 volts and power conversion efficiency of over 17% on small areas and 14.7% on 0.715 cm(2) cells. By…

• SF
  Seventh Framework Programme

  Award: FP7/2007-2013
• EA
  Engineering and Physical Sciences Research Council

  Awards: EP/M014797/1, EP/L024667/1, EP/M024881/1, EP/M024881/1, EP/M014797/1
• OO
  Office of Naval Research
• HE
  H2020 European Research Council