Compared to bulk perovskites, charge transport in perovskite quantum dot (PQD) solids is limited. To address this issue, energetically aligned capping ligands were used to prepare methylammonium lead bromide (MAPbBr₃) PQDs toward enhancing surface charge carrier density in PQD solids. Trans-cinnamic acid (TCA) and its derivates, functionalized with electron-donating or electron-withdrawing groups to modulate energy levels, are used as passivating exciton-delocalizing ligands (EDLs) to decrease the energy gap with respect to the PQD core. 3,3-Diphenylpropylamine (DPPA) ligand is shown to stabilize EDLs on the PQD surface through π–π stacking intermolecular interaction, mitigating charge trapping and nonradiative decay. Passivation using EDLs in combination with DPPA increases the photoluminescence (PL) quantum yield (QY) (90%), photoconductivity, extraction, mobility, transport time, and lifetime of charge carriers in PQD solids. Prototype PQD-based light-emitting diodes (LEDs) were demonstrated with a low turn-on voltage of 2.5 V.

中文翻译：

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用能量对准的共轭封端配体增强钙钛矿量子点固体中的电荷载流子离域。

与块状钙钛矿相比，钙钛矿量子点（PQD）固体中的电荷传输受到限制。为了解决这个问题，采用能量对齐的封端配体制备了甲基铵溴化铅（MAPbBr ₃）PQD，以提高PQD固体中的表面电荷载流子密度。用给电子或吸电子基团官能化以调节能级的反式肉桂酸（TCA）及其衍生物用作钝化激子离域配体（EDL），以减少相对于PQD核的能隙。3,3-二苯丙胺（DPPA）配体通过π–π分子间相互作用堆叠，可稳定PQD表面的EDL，从而减轻电荷俘获和非辐射衰减。使用EDL与DPPA结合进行钝化可提高PQD固体中的光致发光（PL）量子产率（QY）（90％），光电导性，萃取率，迁移率，传输时间和电荷载流子寿命。演示了基于PQD的原型发光二极管（LED）的低开启电压为2.5V。