A multiscale ion diffusion framework sheds light on the diffusion–stability–hysteresis nexus in metal halide perovskites
A multiscale ion diffusion framework sheds light on the diffusion–stability–hysteresis nexus in metal halide perovskites
复制标题
DOI：
10.1038/s41563-023-01488-2
复制
发表时间：
2023-02
期刊：
影响因子：
41.2
通讯作者：
Masoud Ghasemi;Boyu Guo;Kasra Darabi;Tonghui Wang;Kai Wang;Chiung-Wei Huang;Benjamin M. Lefler;Laine Taussig;Mihirsinh Chauhan;Garrett Baucom;Taesoo Kim;Enrique D. Gomez;J. Atkin;Shashank Priya;A. Amassian
中科院分区：
文献类型：
--
作者：
Masoud Ghasemi;Boyu Guo;Kasra Darabi;Tonghui Wang;Kai Wang;Chiung-Wei Huang;Benjamin M. Lefler;Laine Taussig;Mihirsinh Chauhan;Garrett Baucom;Taesoo Kim;Enrique D. Gomez;J. Atkin;Shashank Priya;A. Amassian
稳定性和电流-电压滞后是金属卤化物钙钛矿商业化的主要障碍。这两种现象都与离子迁移有关，坊间证据表明，稳定的器件产生低滞后。然而，复杂的稳定性-滞后联系的潜在机制仍然难以捉摸。在这里，我们提出了一个多尺度扩散框架，它描述了多晶金属卤化物钙钛矿中空位介导的卤化物扩散，区分了快速的晶界扩散系数和慢两到四个数量级的体积扩散系数。我们的结果揭示了晶界激活能与体积扩散之间的反向关系，即具有较小体积扩散系数的稳定金属卤化物钙钛矿与较大的晶界扩散系数和较小的磁滞相关。金属卤化物钙钛矿中多尺度卤化物扩散的阐明揭示了粒子体积中离子迁移与晶界之间的复杂的内部耦合，这反过来可以预测金属卤化物钙钛矿的稳定性和滞后，为解决该领域的突出挑战提供了一条更清晰的途径。
Stability and current–voltage hysteresis stand as major obstacles to the commercialization of metal halide perovskites. Both phenomena have been associated with ion migration, with anecdotal evidence that stable devices yield low hysteresis. However, the underlying mechanisms of the complex stability–hysteresis link remain elusive. Here we present a multiscale diffusion framework that describes vacancy-mediated halide diffusion in polycrystalline metal halide perovskites, differentiating fast grain boundary diffusivity from volume diffusivity that is two to four orders of magnitude slower. Our results reveal an inverse relationship between the activation energies of grain boundary and volume diffusions, such that stable metal halide perovskites exhibiting smaller volume diffusivities are associated with larger grain boundary diffusivities and reduced hysteresis. The elucidation of multiscale halide diffusion in metal halide perovskites reveals complex inner couplings between ion migration in the volume of grains versus grain boundaries, which in turn can predict the stability and hysteresis of metal halide perovskites, providing a clearer path to addressing the outstanding challenges of the field.