Thickness dependent Carrier Lifetime and Mobility for MAPbBr3 Single Crystals
Thickness dependent Carrier Lifetime and Mobility for MAPbBr3 Single Crystals
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MAPbBr3 单晶的厚度相关载流子寿命和迁移率
DOI：
10.1016/j.mtphys.2020.100240
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发表时间：
2020
影响因子：
11.5
通讯作者：
Guo Chunlei
中科院分区：
文献类型：
--
作者：
Xing Jun;Zou Yuting;Zhao Chen;Yu Zhi;Shan Yuwei;Kong Wenchi;Zheng Xin;Li Xiuyun;Yu Weili;Guo Chunlei
载流子转移是钙钛矿基光电转换的关键过程。它与晶界、晶粒尺寸、接触层有密切关系。理解这种关系对于揭示钙钛矿材料的固有特性和器件优化具有重要意义。然而，载流子传输特性（包括载流子寿命和迁移率）对厚度的依赖性研究较少，尽管这是几乎所有钙钛矿材料器件的关键问题。在这里，我们发现，随着 MAPbBr3 钙钛矿单晶（PSC）的厚度从 1.47 μm 增加到 10.55 μm，MAPbBr3 的载流子寿命从 70 ns 减少到 30 ns，载流子迁移率从 97 cm2V−1s−1 减少到 57 cm2V−1s−1，但在非常厚的样品中它们变得恒定。此外，还发现随着晶体厚度从1.47μm增加到10.55μm，表层范围逐渐从12nm增加到31nm。表面复合速度和表面缺陷（陷阱）密度进一步证实薄PSC表现出较小的表面层范围。最后提出了PSC的三层载波传输模型。该研究为PSC光电器件的优化设计提供指导。
Carrier transfer is a key process for perovskite-based photoelectric conversion. It has a close relationship with grain boundaries, grain size, and contact layers. Understanding this relationship is of great significance for revealing the inherent characteristics of perovskite materials and for devices optimization. However, the dependence of carrier transfer characteristics (including carrier lifetime and mobility) on thickness is less studied, although which is a key issue for almost all perovskite material devices. Here we find that as the thickness of MAPbBr3perovskite single crystal (PSC) increases from 1.47 μm to 10.55 μm, the carrier lifetime of MAPbBr3decreases from 70 ns to 30 ns, and the carrier mobility decreases from 97 cm2V−1s−1to 57 cm2V−1s−1, but they become constant in very thick samples. In addition, it was found that as the crystal thickness increased from 1.47 μm to 10.55 μm, the surface layer range gradually increased from 12 nm to 31 nm. The surface recombination velocity and surface defect (trap) density further confirmed that the thin PSC exhibited a small surface layer range. Finally, a three-layer carrier transmission model of PSC is proposed. This research provides guidance for the optimal design of PSC optoelectronic devices.