Low-temperature-gradient crystallization for multi-inch high-quality perovskite single crystals for record performance photodetectors
Low-temperature-gradient crystallization for multi-inch high-quality perovskite single crystals for record performance photodetectors
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用于创纪录性能光电探测器的多英寸高质量钙钛矿单晶的低温梯度结晶
DOI：
10.1016/j.mattod.2018.04.002
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发表时间：
2019-01-01
期刊：
影响因子：
24.2
通讯作者：
Liu, Shengzhong (Frank)
中科院分区：
文献类型：
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作者：
Liu, Yucheng;Zhang, Yunxia;Liu, Shengzhong (Frank)
有机铅卤化物钙钛矿单晶材料具有优异的光电性能，但由于缺乏大尺寸高质量钙钛矿单晶的制备方法，限制了其实际应用。在此，我们报告了我们开发的低温度梯度结晶（LTGC）方法，用于高质量的CH 3 NH3 PbBr 3（MAPbBr（3））钙钛矿单晶，其横向尺寸高达2英寸。理论分析表明，在最佳单晶生长区内，应采用较小的温度梯度来抑制生长条件，特别是溶液浓度。作为温度函数的溶解度曲线在类似于60 ℃时显示出尖锐的转折点，在该转折点上，一阶溶解度导数（dC/dT）显示出非常不同的行为：在该温度以下，dC/dT随着温度的升高而显著变化，而在该温度以上，dC/dT进入平台，在该平台处进一步的温度变化对导数几乎没有影响，这意味着在低于该温度下可以获得相当大的晶体生长速率和结晶产率。利用这一发现，通过LTGC方法获得了高质量的47 × 41 × 14 mm大的MAPbBr 3单晶。该单晶在文献报道的所有MAPbBr 3材料中表现出最好的光电质量，包括最佳的陷阱态密度、迁移率、载流子寿命和扩散长度。这些上级光电性能进一步转化为高性能平面光电探测器。该器件具有高的工作稳定性、高的外量子效率（13，453%）、高达8 × 10（13）Jones的优异探测率和15.8 ls的快速响应速度。据我们所知，无论是探测能力和响应速度是最好的所有MAPbBr（3）的设备中报告的日期。钙钛矿单晶独特的合成方法和优异的结晶质量使其成为下一代光电器件的有希望的候选者。
With their excellent optoelectronic properties, the practical application of single-crystalline organolead halide perovskite materials is now limited by the lack of a method to prepare high-quality perovskite single crystals in large dimension. Herein, we report our development of a low-temperature-gradient crystallization (LTGC) method for high-quality CH3NH3PbBr3 (MAPbBr(3)) perovskite single crystals with lateral dimension as large as two inches. The theoretical analysis suggests that a small temperature gradient should be used to restrain the growth condition, particularly the solution concentration, within the optimal single-crystal-growth (OSCG) zone. The solubility curve as a function of temperature reveals a sharp turning point at similar to 60 degrees C, across which the first-order solubility derivative (dC/dT) shows very different behaviors: below this temperature, the dC/dT changes dramatically as the temperature increases, while above this temperature, the dC/dT enters a plateau where further temperature change has little effect on the derivative, meaning that one can attain both a substantial crystal growth rate and crystallization yield below this temperature. Utilizing this discovery, a MAPbBr3 single crystal as large as 47 x 41 x 14 mm is obtained with high quality via the LTGC method. The single crystal exhibits the best optoelectronic quality among all MAPbBr3 materials reported in the literature, including the best trap state density, mobility, carrier lifetime, and diffusion length. These superior optoelectronic properties are further transferred into a high-performance planar photodetector. The device exhibits high operational stability, high external quantum efficiency (13,453%), excellent detectivity as high as 8 x 10(13) Jones, and a fast response speed as quick as 15.8 ls. To our knowledge, both the detectivity and the response speed are the best among all MAPbBr(3) devices reported to date. The unique synthesis method and excellent crystalline quality of the perovskite single crystals make them promising candidates for the next generation of optoelectronic devices.