Long-Distance Charge Carrier Funneling in Perovskite Nanowires Enabled by Built-in Halide Gradient.
Long-Distance Charge Carrier Funneling in Perovskite Nanowires Enabled by Built-in Halide Gradient.
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DOI：
10.1021/jacs.6b10512
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发表时间：
2017-01
影响因子：
15
通讯作者：
Wenming Tian;J. Leng;Chunyi Zhao;Shengye Jin
中科院分区：
文献类型：
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作者：
Wenming Tian;J. Leng;Chunyi Zhao;Shengye Jin
有机铅卤化物钙钛矿中优异的载流子传输是许多钙钛矿器件高性能的主要贡献者之一。由于钙钛矿的多功能湿化学合成和加工，仍然存在通过纳米工程进一步增强载流子传输的可能性。在这里，我们报告了从纯CH3NH3PbI3 NWs的一端开始，通过固-固离子交换反应成功合成了溴化物梯度CH3NH3PbBrxI3-x单晶纳米线（NWs），并通过局部光致发光（PL）和能量色散X射线光谱（EDS）测量证实了这一点。由于内置的卤化物梯度，长距离载流子传输是由能量漏斗驱动的，而不是自发的载流子扩散。事实上，局部PL动力学证明载流子的有效传输仅在几微米内从高带隙富含溴化物区域到低带隙富含碘区域。因此，这些卤化物梯度纳米线可能会在需要长距离和定向传输激发能量的各种光电器件中得到应用。
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 CH3NH3PbBrxI3-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.