Author(s): Peng, L (Peng, Li); Liu, LX (Liu, Lixiang); Du, SC (Du, Sichao); Bodepudi, SC (Bodepudi, Srikrishna Chanakya); Li, LF (Li, Lingfei); Liu, W (Liu, Wei); Lai, RC (Lai, Runchen); Cao, XX (Cao, Xiaoxue); Fang, WZ (Fang, Wenzhang); Liu, YJ (Liu, Yingjun); Liu, XY (Liu, Xinyu); Lv, J (Lv, Jianhang); Abid, M (Abid, Muhammad); Liu, JX (Liu, Junxue); Jin, SY (Jin, Shengye); Wu, KF (Wu, Kaifeng); Lin, ML (Lin, Miao-Ling); Cong, X (Cong, Xin); Tan, PH (Tan, Ping-Heng); Zhu, HM (Zhu, Haiming); Xiong, QH (Xiong, Qihua); Wang, XM (Wang, Xiaomu); Hu, WD (Hu, Weida); Duan, XF (Duan, Xiangfeng); Yu, B (Yu, Bin); Xu, Z (Xu, Zhen); Xu, Y (Xu, Yang); Gao, C (Gao, Chao)

Source: INFOMAT Article Number: e12309 DOI: 10.1002/inf2.12309 Early Access Date: MAR 2022

Abstract: Graphene with linear energy dispersion and weak electron-phonon interaction is highly anticipated to harvest hot electrons in a broad wavelength range. However, the limited absorption and serious backscattering of hot-electrons result in inadequate quantum yields, especially in the mid-infrared range. Here, we report a macroscopic assembled graphene (nMAG) nanofilm/silicon heterojunction for ultrafast mid-infrared photodetection. The assembled Schottky diode works in 1.5-4.0 mu m at room temperature with fast response (20-30 ns, rising time, 4 mm(2) window) and high detectivity (1.6 x 10(11) to 1.9 x 10(9) Jones from 1.5 to 4.0 mu m) under the pulsed laser, outperforming single-layer-graphene/silicon photodetectors by 2-8 orders. These performances are attributed to the greatly enhanced photo-thermionic effect of electrons in nMAG due to its high light absorption (similar to 40%), long carrier relaxation time (similar to 20 ps), low work function (4.52 eV), and suppressed carrier number fluctuation. The nMAG provides a long-range platform to understand the hot-carrier dynamics in bulk 2D materials, leading to broadband and ultrafast MIR active imaging devices at room temperature.

Accession Number: WOS:000770401300001

eISSN: 2567-3165

Full Text: https://onlinelibrary.wiley.com/doi/10.1002/inf2.12309