Li Guili, Zhang Xiaoxian, Wang Yongsheng, Bai Zhiying, Zhao Hui, He Jiaqi, He Dawei
Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, China.
Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, USA.
Nanoscale. 2023 Sep 21;15(36):14994-14999. doi: 10.1039/d3nr03173j.
We investigate the photocarrier dynamics in bulk PdSe, a layered transition metal dichalcogenide with a novel pentagonal structure and unique electronic and optical properties. Using femtosecond transient absorption microscopy, we study the behavior of photocarriers in mechanically exfoliated bulk PdSe flakes at room temperature. By employing a 400 nm ultrafast laser pulse, electron-hole pairs are generated, and their dynamics are probed using an 800 nm detection pulse. Our findings reveal that the lifetime of photocarriers in bulk PdSe is approximately 210 ps. Furthermore, by spatially resolving the differential reflection signal, we determine a photocarrier diffusion coefficient of about 7.3 cm s. Based on these results, we estimate a diffusion length of around 400 nm and a photocarrier mobility of approximately 300 cm V s. These results shed light on the ultrafast optoelectronic properties of PdSe, offer valuable insights into photocarriers in this emerging material, and enable design of high-performance optoelectronic devices based on PdSe.
我们研究了块状PdSe中的光载流子动力学，PdSe是一种具有新型五边形结构以及独特电子和光学性质的层状过渡金属二硫属化物。利用飞秒瞬态吸收显微镜，我们在室温下研究了机械剥离的块状PdSe薄片中光载流子的行为。通过使用400 nm的超快激光脉冲产生电子 - 空穴对，并使用800 nm探测脉冲探测其动力学。我们的研究结果表明，块状PdSe中光载流子的寿命约为210 ps。此外，通过对差分反射信号进行空间分辨，我们确定了约7.3 cm² s⁻¹的光载流子扩散系数。基于这些结果，我们估计扩散长度约为400 nm，光载流子迁移率约为300 cm² V⁻¹ s⁻¹。这些结果揭示了PdSe的超快光电特性，为这种新兴材料中的光载流子提供了有价值的见解，并有助于基于PdSe设计高性能光电器件。
