Ultrafast and Sensitive Self-Powered Photodetector Featuring Self-Limited Depletion Region and Fully-Depleted Channel with van der Waals Contacts

Mingjin Dai, Hongyu Chen, Fakun Wang, Mingsheng Long, Huiming Shang, Yunxia Hu, Wen Li, Chuanyang Ge, Jia Zhang, Tianyou Zhai, Yongqing (Richard) Fu, PingAn Hu

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)

Abstract

Self-powered photodetectors with great potential for implanted medical diagnosis and smart communications have been severely hindered by the difficulty of simultaneously achieving high sensitivity and fast response speed. Here, we report an ultrafast and highly sensitive self-powered photodetector based on two-dimensional (2D) InSe, which is achieved by applying a device architecture design and generating ideal Schottky or ohmic contacts on 2D layered semiconductors, which are difficult to realize in the conventional semiconductors owing to their surface Fermi-level pinning. The as-fabricated InSe photodiode features a maximal lateral self-limited depletion region and a vertical fully depleted channel. It exhibits a high detectivity of 1.26 × 1013 Jones and an ultrafast response speed of ∼200 ns, which breaks the response speed limit of reported self-powered photodetectors based on 2D semiconductors. The high sensitivity is achieved by an ultralow dark current noise generated from the robust van der Waals (vdW) Schottky junction and a high photoresponsivity due to the formation of a maximal lateral self-limited depletion region. The ultrafast response time is dominated by the fast carrier drift driven by a strong built-in electric field in the vertical fully depleted channel. This device architecture can help us to design high-performance photodetectors utilizing vdW layered semiconductors.

Original languageEnglish
Pages (from-to)9098-9106
Number of pages9
JournalACS Nano
Volume14
Issue number7
Early online date30 Jun 2020
DOIs
Publication statusPublished - 28 Jul 2020

Fingerprint

Dive into the research topics of 'Ultrafast and Sensitive Self-Powered Photodetector Featuring Self-Limited Depletion Region and Fully-Depleted Channel with van der Waals Contacts'. Together they form a unique fingerprint.

Cite this