Kinetic Isotope Effects Provide Experimental Evidence for Proton Tunneling in Methylammonium Lead Triiodide Perovskites
作者:Yan-Fang Chen、Yu-Tang Tsai、Lionel Hirsch、Dario M. Bassani
DOI:10.1021/jacs.7b09526
日期:2017.11.15
occurrence of proton tunneling in MAPbI3 hybrid organic inorganic perovskites is demonstrated through the effect of isotopic labeling of the methylammonium (MA) component on the dielectric permittivity response. Deuteration of the ammonium group results in the acceleration of proton migration (inverse primary isotope effect), whereas deuteration of the methyl group induces a normal secondary isotope effect
通过同位素标记甲基铵(MA)组分对介电常数响应的影响,证明了MAPbI 3杂化有机无机钙钛矿中质子隧穿的发生。铵基团的氘代导致质子迁移加速(初级同位素反作用),而甲基基团的氘代诱导正常的次级同位素效应。对于四方相和正交相,质子迁移的活化能分别计算为50和27 meV,在铵基团氘化后降低。较低的激活势垒和偏离单位前指数因子之比(A H / A D= 0.3–0.4)与质子迁移的隧穿机制一致。由于两种材料之间的非本征离子迁移,PEDOT:PSS空穴传输层的氘代导致的行为介于氘代钙钛矿和未氘代钙钛矿之间。