Hu Yiping, Zhu Qinghai, Sun Jiabao, Sun Yijun, Hanagata Nobutaka, Xu Mingsheng
School of Micro-Nano Electronics, State Key Laboratory of Si & Advanced Semiconductor Materials, Zhejiang University, Hangzhou 310027, People's Republic of China.
College of Information Science & Electronic Engineering, Micro-Nano Fabrication Center, Zhejiang University, Hangzhou 310007, People's Republic of China.
Nanotechnology. 2023 Sep 22;34(49). doi: 10.1088/1361-6528/acf672.
Two-dimensional (2D) PdSefilm has the characteristics of adjustable bandgap, high carrier mobility, and high stability. Photodetector (PD) based on 2D PdSeexhibits wide spectral self-driving features, demonstrating enormous potential in the field of optical detection. Here, we design and fabricate PdSe/Si heterojunction PDs with various thicknesses of the PdSefilms from 10 to 35 nm. Due to the enhancement of light absorption capacity and built-in electric field of heterojunction, the photodetector with thicker PdSefilm can generate more photo-generated carriers and effectively separate them to form a large photocurrent, thus showing more excellent photodetection performance. The responsivity and specific detectivity of the PdSe/Si PDs with 10 nm, 20 nm, and 35 nm PdSefilms are 2.12 A Wand 6.72 × 10Jones, 6.17 A Wand 1.95 × 10Jones, and 8.02 A Wand 2.54 × 10Jones, respectively (808 nm illumination). The PD with 35 nm PdSefilm exhibits better performance than the other two PDs, with the rise/fall times of 15.8s/138.9s at= 1 kHz and the cut-off frequency of 8.6 kHz. Furthermore, we demonstrate that the properties of PdSe/Si PD array have excellent uniformity and stability at room temperature and shows potential for image sensing in the UV-vis-NIR wavelength range.
二维（2D）PdSe薄膜具有带隙可调、载流子迁移率高和稳定性高的特点。基于2D PdSe的光电探测器（PD）具有宽光谱自驱动特性，在光学检测领域展现出巨大潜力。在此，我们设计并制备了具有10至35nm不同厚度PdSe薄膜的PdSe/Si异质结光电探测器。由于异质结光吸收能力和内建电场的增强，具有较厚PdSe薄膜的光电探测器能够产生更多光生载流子并有效地将它们分离以形成大的光电流，从而表现出更优异的光电探测性能。具有10nm、20nm和35nm PdSe薄膜的PdSe/Si光电探测器在808nm光照下的响应度和比探测率分别为2.12A/W和6.72×10Jones、6.17A/W和1.95×10Jones、8.02A/W和2.54×10Jones。具有35nm PdSe薄膜的光电探测器表现出比其他两个光电探测器更好的性能，在1kHz时的上升/下降时间为15.8s/138.9s，截止频率为8.6kHz。此外，我们证明了PdSe/Si PD阵列的性能在室温下具有出色的均匀性和稳定性，并在紫外-可见-近红外波长范围内显示出图像传感的潜力。
