Polarization-Sensitive Self-Powered Type-II GeSe/MoS₂ van der Waals Heterojunction Photodetector

Abstract

Polarization-sensitive photodetectors are highly desirable for high-performance optical signal capture and stray light shielding in order to enhance the capability for detection and identification of targets in dark, haze, and other complex environments. Usually, filters and polarizers are utilized for conventional devices to achieve polarization-sensitive detection. Herein, to simplify the optical system, a two-dimensional self-powered polarization-sensitive photodetector is fabricated based on a stacked GeSe/MoS2 van der Waals (vdW) heterojunction which facilitates efficient separation and transportation of the photogenerated carriers because of type-II band alignment. Accordingly, a high-performance self-powered photodetector is achieved with merits of a very large on–off ratio photocurrent at zero bias of currently 104 and a high responsivity (R λ) of 105 mA/W with an external quantum efficiency of 24.2%. Furthermore, a broad spectral photoresponse is extended from 380 to 1064 nm owing to the high absorption coefficient in a wide spectral region. One of the key benefits from these highly anisotropic orthorhombic structures of layered GeSe is self-powered polarization-sensitive detection with a peak/valley ratio of up to 2.95. This is realized irradiating with a 532 nm wavelength laser with which a maximum photoresponsivity of up to 590 mA/W is reached when the input polarization is parallel to the armchair direction. This work provides a facile route to fabricate self-powered polarization-sensitive photodetectors from GeSe/MoS2 vdW heterojunctions for integrated optoelectronic devices.

A review of molybdenum disulfide (MoS2) based photodetectors: from ultra-broadband, self-powered to flexible devices

“…GeSe/MoS 2 photodetector retained constant photoresponse under applied reverse bias because of the reduced carrier conduction within depletion region. Xin et al 424 fabricated polarization-sensitive self-powered photodetectors using type-II band aligned GeSe/MoS 2 vdWHs to increase photoresponse spectrum and support efficient separation as well as transportation of the photoexcited charge carriers. GeSe/MoS 2 p-n heterojunctions were developed using mechanically exfoliated GeSe and MoS 2 nanoakes on p-doped Si substrate having a SiO 2 lm of 300 nm thickness.…”

High Performance Self‐Driven Polarization‐Sensitive Photodetectors Based on GeAs/InSe Heterojunction

“…[ 24,25 ] For example, a type‐II self‐powered GeSe/MoS 2 (anisotropic/isotropic) heterojunction was recently reported with a high responsivity of 105 mA/W and anisotropic photocurrent ratio of 2.95. [ 26 ]…”

Highly sensitive infrared polarized photodetector enabled by out-of-plane PSN architecture composing of p-MoTe2, semimetal-MoTe2 and n-SnSe2

“…As a typical 2D semimetal, graphene shows the great success in high-speed and broadband photodetection applications [12,13]. Recently, type-II Weyl semimetal such as 1T-MoTe 2 [14], 1T-WTe 2 [15], and TaIrTe 4 [16] have also been explored for broadband photodetection. It is noted that these classes of 2D semimetals possess low-symmetric crystalline structure that has led to the anisotropic optical and electrical properties, giving rise to the additional capability for linearly polarized light detection [17][18][19].…”