Tunable internal quantum well alignment in rationally designed oligomer-based perovskite films deposited by resonant infrared matrix-assisted pulsed laser evaporation
Tunable internal quantum well alignment in rationally designed oligomer-based perovskite films deposited by resonant infrared matrix-assisted pulsed laser evaporation
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DOI：
10.1039/c9mh00366e
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发表时间：
2019-10-01
影响因子：
13.3
通讯作者：
Mitzi, David B.
中科院分区：
文献类型：
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作者：
Dunlap-Shohl, Wiley A.;Barraza, E. Tomas;Mitzi, David B.
掺入共轭有机阳离子的杂化钙钛矿使有机和无机结构组分之间能够实现不寻常的载流子相互作用，但由于组分的化学/物理特性(例如，溶解性、热稳定性)不同，很难制备成薄膜。在这里，我们展示了共振红外基质辅助脉冲激光蒸发(RIR-Maple)缓解了这些挑战，使得能够轻松地沉积含有可变长度的低聚硫吩阳离子的卤化铅基钙钛矿薄膜。密度泛函理论(DFT)预测了合适的有机和无机部分，它们可以形成具有靶向发光或激子分离/猝灭的量子势垒结构。RIR-Maple沉积的薄膜可以通过光学测量来证实这些预测，这些测量进一步显示了超越传统量子阱模型的激发态行为-即，通过适当选择特殊合成的有机/无机部分，组分间载流子转移有效地将激子从有机分子中的单态转变为三重态，而系统间交叉通常不能与复合竞争。这些观测结果显示了钙钛矿混合量子阱中独特的多功能激发态行为，以及将密度泛函理论、有机合成、RIR-Maple和光谱学相结合在筛选/制备合理设计的复杂结构方面的价值。
Hybrid perovskites incorporating conjugated organic cations enable unusual charge carrier interactions among organic and inorganic structural components, but are difficult to prepare as films due to disparate component chemical/physical characteristics (e.g., solubility, thermal stability). Here we demonstrate that resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) mitigates these challenges, enabling facile deposition of lead-halide-based perovskite films incorporating variable-length oligothiophene cations. Density functional theory (DFT) predicts suitable organic and inorganic moieties that form quantum-well-like structures with targeted luminescence or exciton separation/quenching. RIR-MAPLE-deposited films enable confirmation of these predictions by optical measurements, which further display excited state behavior transcending traditional quantum-well models-i.e., with appropriate selection of specially synthesized organic/inorganic moieties, intercomponent carrier transfer efficiently converts excitons from singlet to triplet states in organics for which intersystem crossing cannot ordinarily compete with recombination. These observations demonstrate the uniquely versatile excited-state behavior in hybrid perovskite quantum wells, and the value of integrating DFT, organic synthesis, RIR-MAPLE and spectroscopy for screening/preparing rationally devised complex structures.