论文标题
对称分析中掺杂的钙钛矿纳米晶体中发光增强的通用机理
Universal mechanism of luminescence enhancement in doped perovskite nanocrystals from symmetry analysis
论文作者
论文摘要
金属 - 半钙钛矿纳米晶体表现出极好的光电特性,用于发光应用。具有各种金属(M2+)的等值掺杂可用于量身定制和增强其光发射。尽管对于最大化性能至关重要,但仍然缺少对这种兴奋剂的通用工作机制的理解。在这里,我们直接比较纳米晶体的光学特性,该纳米晶体包含在相同的合成条件下制造的最常用的掺杂剂。我们首次明确地展示了第一原理计算和分子轨道理论的支持,表明元素不特定的对称性破坏而不是元素特异性电子效应在相关条件下占主导地位。大多数掺杂剂对钙钛矿电子结构的影响主要基于局部晶格周期性破裂和产生的荷载载体定位,从而增强了辐射重组,而掺杂剂特异性杂交效应起次要作用。我们的结果提出了选择掺杂剂的特定指南,以最大程度地提高所需光电设备中钙钛矿发射器的性能。
Metal-halide perovskite nanocrystals have demonstrated excellent optoelectronic properties for light-emitting applications. Isovalent doping with various metals (M2+) can be used to tailor and enhance their light emission. Although crucial to maximize performance, an understanding of the universal working mechanism for such doping is still missing. Here, we directly compare the optical properties of nanocrystals containing the most commonly employed dopants, fabricated under identical synthesis conditions. We show for the first time unambiguously and supported by first principles calculations and molecular orbital theory that element-unspecific symmetry-breaking rather than element-specific electronic effects dominate these properties under device-relevant conditions. The impact of most dopants on the perovskite electronic structure is predominantly based on local lattice periodicity breaking and resulting charge carrier localization, leading to enhanced radiative recombination, while dopant-specific hybridization effects play a secondary role. Our results suggest specific guidelines for selecting a dopant to maximize the performance of perovskite emitters in the desired optoelectronic devices.