Long-Distance Charge Carrier Funneling in Perovskite Nanowires Enabled by Built-in Halide Gradient

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• 作者：Wenming Tian ; Jing Leng ; Chunyi Zhao ; Shengye Jin
• 刊名：Journal of the American Chemical Society
• 出版年：2017
• 出版时间：January 18, 2017
• 年：2017
• 卷：139
• 期：2
• 页码：579-582
• 全文大小：287K
• ISSN：1520-5126

文摘

The excellent charge carrier transportation in organolead halide perovskites is one major contributor to the high performance of many perovskite-based devices. There still exists a possibility for further enhancement of carrier transportation through nanoscale engineering, owing to the versatile wet-chemistry synthesis and processing of perovskites. Here we report the successful synthesis of bromide-gradient CH₃NH₃PbBr_xI_3–x single-crystalline nanowires (NWs) by a solid-to-solid ion exchange reaction starting from one end of pure CH₃NH₃PbI₃ NWs, which was confirmed by local photoluminescence (PL) and energy dispersive X-ray spectroscopy (EDS) measurements. Due to the built-in halide gradient, the long-distance carrier transportation was driven by the energy funnel, rather than the spontaneous carrier diffusion. Indeed, local PL kinetics demonstrated effective charge carrier transportation only from the high-bandgap bromide-rich region to the low-bandgap iodine-rich region over a few micrometers. Therefore, these halide gradient NWs might find applications in various optoelectronic devices requiring long-distance and directional delivery of excitation energy.