Can Pb-Free Halide Double Perovskites Support High-Efficiency Solar Cells?

The methylammonium lead halides have become champion photoactive semiconductors for solar cell applications; however, issues still remain with respect to chemical instability and potential toxicity. Recently, the Cs 2 AgBiX 6 (X = Cl, Br) double perovskite family has been synthesized and investigated as stable nontoxic replacements. We probe the chemical bonding, physical properties, and cation anti-site disorder of Cs 2 AgBiX 6 and related compounds from first-principles. We demonstrate that the combination of Ag(I) and Bi(III) leads to the wide indirect band gaps with large carrier effective masses owing to a mismatch in angular momentum of the frontier atomic orbitals. The spectroscopically limited…

• EA
  Engineering and Physical Sciences Research Council

  Awards: EP/N01572X/1, EP/J017361/1, EP/M009580/1, EP/L017792/1, EP/K016288/1, EP/N01572X/1, EP/L000202, EP/M009580/1, EP/K016288/1, EP/J017361/1, EP/L017792/1
• ER
  European Research Council

  Award: 277757