论文标题
Anharmonicition驱动的Rashba共螺旋激子打破量子效率的限制
Anharmonicity-driven Rashba co-helical excitons break quantum efficiency limitation
论文作者
论文摘要
封闭壳发光二极管（LED）遭受了由光学无效的三胞胎激子施加的内部量子效率（IQE）限制。在这里，我们展示了铅壁壁炉 - 玻璃盐（LHPS）APBX $ _3 $（A = CS/CN $ _2 $ H $ _5 $; X = Cl/Br/I）的未发现的排放机制，以规避封闭壳LED的效率限制。尽管在反转对称的LHP中被光学无效的$ j = 0 $禁止，但沿PB的立体化学和沿假想的A $^+\ cdots $ x $ x $^ - $ x $^ - （t $ _ {1U} $）的横向选择（tosers）的模式，介绍的模式，介绍的模式，介绍了跨性别（ Rashba-Dresselhaus自旋轨道耦合（RD-SOC）。这导致了明亮的共螺旋和深色抗螺旋激子。多体理论和第一原理计算确认，光学活跃的共螺旋激子是有机/无机LHP中最低的激发态。因此，RD-SOC可以通过使用Anharmonicity来驱动以实现理想的50 $ \％$ IQE，这超过了25美元$ \％$ iqe限制的封闭壳LED。
Closed-shell light-emitting diodes (LEDs) suffer from the internal quantum efficiency (IQE) limitation imposed by optically inactive triplet excitons. Here we show an undiscovered emission mechanism of lead-halide-perovskites (LHPs) APbX$_3$ (A=Cs/CN$_2$H$_5$; X=Cl/Br/I) that circumvents the efficiency limit of closed-shell LEDs. Though efficient emission is prohibited by optically inactive $J=0$ in inversion symmetric LHPs, the anharmonicity arising from stereochemistry of Pb and resonant orbital-bonding network along the imaginary A$^+\cdots$X$^-$ (T$_{1u}$) transverse optical (TO) modes, breaks the inversion symmetry and introduces disorder and Rashba-Dresselhaus spin-orbit coupling (RD-SOC). This leads to bright co-helical and dark anti-helical excitons. Many-body theory and first-principles calculations affirm that the optically active co-helical exciton is the lowest excited state in organic/inorganic LHPs. Thus, RD-SOC can drive to achieve the ideal 50 $\%$ IQE by utilizing anharmonicity, much over the 25 $\%$ IQE limitation for closed-shell LEDs.
