Du Xinyuan, Liu Yingmeng, Pan Weicheng, Pang Jincong, Zhu Jinsong, Zhao Shan, Chen Chao, Yu Yu, Xiao Zewen, Niu Guangda, Tang Jiang
Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China.
Optics Valley Laboratory, Hubei, 430074, China.
Adv Mater. 2022 Apr;34(17):e2110252. doi: 10.1002/adma.202110252. Epub 2022 Mar 18.
Controlling the carrier polarity and concentration underlies most electronic and optoelectronic devices. However, for the intensively studied lead halide perovskites, the doping tunability is inefficient. In this work, taking CsPbBr as an example, it is revealed that the coexistence of metallic Pb or CsBr /Br , rather than the precursor ratio, can provide Pb-rich/Br-poor or Br-rich/Pb-poor chemical conditions, enabling the tunability of electrical properties from weak n-type, intrinsic, to moderate p-type. Experimentally, under Br -exposure treatment, a shift of the Fermi level as large as 1.00 eV is achieved, which is one of the highest value among all kinds of doping methods. The X-ray detector based on the intrinsic CsPbBr exhibits excellent performance, with a negligible dark-current drift of 7.1 × 10 nA cm s V , a low detection limit of 103.6 nGy s , and a high sensitivity of 9085 μC Gy cm . This work provides a critical understanding and guidance for tuning the electrical properties of lead halide perovskites, which establishes good foundations for achieving intrinsic perovskite semiconductors and also constructing potential homojunction devices.
控制载流子极性和浓度是大多数电子和光电器件的基础。然而，对于经过深入研究的卤化铅钙钛矿来说，其掺杂可调性效率低下。在这项工作中，以CsPbBr为例，研究发现金属Pb或CsBr/Br的共存而非前驱体比例，能够提供富Pb/贫Br或富Br/贫Pb的化学条件，从而实现从弱n型、本征型到中等p型的电学性质可调性。实验上，在Br暴露处理下，实现了高达1.00 eV的费米能级移动，这是所有掺杂方法中最高的值之一。基于本征CsPbBr的X射线探测器表现出优异的性能，暗电流漂移可忽略不计，为7.1×10 nA cm s V，探测下限低至103.6 nGy s，灵敏度高达9085 μC Gy cm。这项工作为调控卤化铅钙钛矿的电学性质提供了关键的理解和指导，为实现本征钙钛矿半导体以及构建潜在的同质结器件奠定了良好基础。
