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

Abstract

The ability to detect linearly polarized light is essential in the field of angle‐dependent optoelectronics and polarization optical applications. To date, most polarization‐sensitive photodetectors are mainly based on single 2D anisotropic materials, which still suffer from the large dark current, from being external bias driven, and from low anisotropy ratio. To address these obstacles, we fabricated a van der Waals (vdW) GeAs/InSe heterojunction with type‐II band alignment achieving a high‐performance self‐driven polarization‐sensitive photodetector. The heterojunction exhibits excellent rectifying characteristics with a current rectification ratio exceeding 103. By operating in photovoltaic mode at zero bias, the device shows a very low dark current of ∼0.1 picoampere, high photoresponsivity of 357 mA/W, and large photo‐switching ratio of 103, yielding a high specific detectivity of 2 × 1011 Jones and photoelectric conversion efficiency (PCE) up to 8%. Benefiting from the anisotropic structure of the GeAs components, the heterojunctions also exhibit self‐driven polarization‐sensitive photodetection with superior anisotropic photocurrent ratio of ∼18 which surpasses state‐of‐the‐art 2D based polarization‐dependent detectors. This work proposes an effective strategy utilizing the anisotropic/isotropic vdW heterojunctions to enable self‐powered and high‐performance polarization‐sensitive photodetectors, opening a new avenue towards the promising potential applications in polarization‐resolved electronics and photonics.

Raman Anisotropy and Polarization-Sensitive Photodetection in 2D Bi2O2Se–WSe2 Heterostructure

“… 19 The dichroism ratio of photocurrent, defined as the value of maximum photocurrent divided by the minimum photocurrent, is calculated to be 2.2 and 4.9 for 405 and 635 nm light, respectively, which implies a high polarization-sensitive performance and is at par with that of other 2D low-symmetric materials. 39 − 41 Figure 6 e,f shows the mapping plot of I – V curves at 405 and 635 nm light with varying light polarization angles, also depicting strong anisotropic photocurrent.…”

Anisotropic Low‐Dimensional Materials for Polarization‐Sensitive Photodetectors: From Materials to Devices

“…The same mechanism has also been verified in GeAs/InSe and MoTe 2 /ReS 2 heterojunctions. [217,218] Recently, a 2D 1T' ReS 2 /ReSe 2 lateral p-n heterojunction (Figure 15d) has been first synthesized exhibiting clear linear dichroism. [155] As shown in Figure 15f, with different angles of polarized light, the transport curves indicate the anisotropic photoresponse owing to the native anisotropy of the TMDbased heterostructure.…”

Mixed-Dimensional InSe–Si Heterojunction Nanostructures for Self-Powered Broadband Photodetectors

“…The current ( I )–voltage ( V ) curves of the InSe–Si heterojunction are displayed in Figure a. The vdWHs show a significant rectifying effect with a large rectification ratio (RR) of 5000 at small bias voltages of ±1 V. As shown in Figure b, the RR of the 2D–3D InSe–Si vdWHs is superior to those of all other 2D InSe-based heterojunctions ,,− ,− and is comparable to those of most transition-metal dichalcogenide-based 2D–3D heterojunctions ,, measured without a gate voltage. The ideality factor ( n ) is 1.1, indicating that the diffusion current is responsible for the current rectifying behavior of the InSe–Si vdWHs.…”

“…(a) I - V curves of the InSe-Si vdWHs. (b) Comparison of the RRs of various 2D InSe-based heterojunctions and mixed-dimensional (2D–3D) vdWHs measured without a gate voltage, including InSe–Se, InSe–Te, InSe–AsP, InSe–GaTe, InSe–BP, MoS 2 –InSe, InSe–GaSe, InSe–GeAs, MoS 2 –Si, WS 2 –Si, and MoSe 2 –Si …”

“…Figure 1b shows the optical image of the vdWHs photodetector; the thickness of the multilayer InSe is 40 nm (Figure S2). 19 InSe−Te, 17 InSe−AsP, 18 InSe−GaTe, 15 InSe−BP, 22 MoS 2 −InSe, 23 InSe−GaSe, 14 InSe−GeAs, 24 MoS 2 −Si, 20 WS 2 −Si, 25 and MoSe 2 −Si. photodetector (detailed calculations are shown in the SI).…”