Defect structure in quantum-cutting <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow><mml:mi>Yb</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:math>-doped <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>CsPb</mml:mi><mml:msub><mml:mi>Cl</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math> perovskites probed by x-ray absorption and atomic pair distribution function analysis
Kyle T. Kluherz, Sebastian T. Mergelsberg, David E. Sommer, Joo Yeon D. Roh, Sarah A. Saslow, Daniel Biner, Karl W. Krämer, Scott T. Dunham, James J. De Yoreo, Daniel R. Gamelin
Abstract
Lead halide perovskite materials doped with lanthanides can exhibit over 100% luminescence quantum yield due to quantum cutting. Defect states related to these dopants are known to play a role in the quantum cutting mechanism, but the structural changes and charge compensation mechanisms induced by these dopants have not been fully explored. Here, the authors use a combination of advanced x-ray techniques and computational modeling to elucidate the structural impact of ytterbium doping in CsPbCl${}_{3}$. The authors find that Yb${}^{3+}$, exclusively in the +3 oxidation state, replaces Pb${}^{2+}$ in the octahedral site with charge compensated by Pb${}^{2+}$ vacancies, providing clear experimental verification of a hypothesized structure.