Giant Photoluminescence Enhancement in CsPbCl3 Perovskite Nanocrystals by Simultaneous Dual-Surface Passivation
Giant Photoluminescence Enhancement in CsPbCl3 Perovskite Nanocrystals by Simultaneous Dual-Surface Passivation
复制标题
DOI：
10.1021/acsenergylett.8b01441
复制
发表时间：
2018-10-01
影响因子：
22
通讯作者：
Mohammed, Omar F.
中科院分区：
文献类型：
--
作者：
Ahmed, Ghada H.;El-Demellawi, Jehad K.;Mohammed, Omar F.
CsPbCl 3钙钛矿纳米晶体（NC）表面局部陷阱态的存在是阻碍这些NC光电应用开发的最大挑战之一。这些缺陷位点的钝化提供了一个有前途的途径，以补救其电子和光学性质，如光致发光量子产率（PLQY）。在此，我们展示了使用三价金属离子盐的合成后双表面处理，即，YCl 3作为一种新的钝化方法，在保持NC尺寸和晶体结构的同时，将PLQY提高到60%。这种显着的增强PLQY沿着与处理的NC样品的平均PL寿命的延长表明有效的钝化的表面缺陷和随后的抑制表面非辐射复合中心的形成。作为光电应用的一个过渡，我们探讨了使用超柔性器件的NC的光电性能;我们发现，YCl 3处理的CsPbCl 3 NC膜表现出一个数量级更大的光电流相比，其未经处理的同行。我们的实验和理论研究结果提供了一个深刻的理解的有效钝化作用的Y3+和Cl-离子的表面上的CsPbCl 3纳米碳，以及提供了一个新的途径，以合成高品质的纳米碳的紫外光转换应用。
The presence of localized trap states on the surface of CsPbCl3 perovskite nanocrystals (NCs) is one of the greatest challenges precluding the development of optoelectronic applications of these NCs. Passivation of these defect sites provides a promising pathway to remediating their electronic and optical properties, such as the photoluminescence quantum yield (PLQY). Herein, we demonstrate a postsynthetic dual-surface treatment using trivalent metal ion salts, i.e., YCl3, as a new passivation approach that enhances the PLQY up to 60% while preserving the NC size and crystal structure. Such remarkable enhancement of the PLQY along with prolongation of the average PL lifetimes of treated NCs samples indicates effective passivation of the surface defects and subsequent suppression of the formation of surface nonradiative recombination centers. As a segue toward optoelectronic applications, we probed the photoelectric performance of the NCs using ultraflexible devices; we found that YCl3-treated CsPbCl3 NC films exhibit an order of magnitude larger photocurrent compared to their nontreated counterparts. Our experimental and theoretical results provide an insightful understanding of the effective passivating roles of Y3+ and Cl- ions on the surface of CsPbCl3 NCs, as well as offering a new path to synthesize high-quality NCs for UV light conversion applications.