Perpendicularly Reversed Polarization Sensitivity of Double‐faced Photodetection based on Sb₂Se₃ Microbelt

Abstract

Low-dimensional polarization-sensitive photodetectors have captured everincreasing attention due to their unique applications in navigation, optical switching, and communication. However, to date, the study of dimensionality-dependent polarization-sensitive photodetectors has not received much attention. Herein, a double-faced polarization-sensitive photodetector based on an individual high-quality Sb 2 Se 3 microbelt is proposed, where both the wide and narrow side facets serve as irradiation targets. Polarization-sensitive measurements reveal the anisotropy in the photocurrents recorded parallel and perpendicular to the long axis of the Sb 2 Se 3 microbelt. Strikingly, the single Sb 2 Se 3 microbelt photodetector reveals the obvious perpendicular reversal with a 90° angle on polarization sensitivity from the wide surface to the narrow surface. With decreasing inclination angle, the anisotropic ratio varies from 1.18 to 0.87 gradually. Interestingly, the photodetector can lose its polarization sensitivity at a particular inclination angle. Angle-resolved polarized Raman spectroscopy confirms the asymmetry and anisotropic character of the Sb 2 Se 3 microbelt. The polarization sensitivity of the Sb 2 Se 3 microbelt photodetectors originates from the optical anisotropy induced by the crystal structure anisotropy, rather than one-dimensional geometry morphological anisotropy. The use of an anisotropic Sb 2 Se 3 microbelt in double-faced polarization-sensitive photodetection may contribute to new functionality in innovative optoelectronic applications.

Junction‐Enhanced Polarization Sensitivity in Self‐Powered Near‐Infrared Photodetectors Based on Sb2Se3 Microbelt/n‐GaN Heterojunction

“…According to the absorption coefficient (≈10 5 cm −1 ) for E // c , the penetration depth is calculated to be ≈100 nm. [ 50 ] It indicates that the photoinduced electrons and holes are partially excited in the depletion region, as shown in Figure 5d. The built‐in electric field in the depletion region can spatially separate carriers, significantly reducing the recombination rate, and thereby, forming a large photocurrent.…”

“…Due to the large thickness of Sb 2 Se 3 MB, the difference in actual absorption is small even if the absorption coefficient ( E // c ) is greatly larger than the absorption coefficient ( E // a ) in the NIR region. [ 50 ] The polarization sensitivity of the MXene/Sb 2 Se 3 MB/MXene vertical PD does not achieve the desired results.…”

Fabrication of High‐Responsivity Sb2Se3‐Based Photodetectors through Selenization Process

“…Figure 7 summarizes the relationship between the responsivity and response time of the 250 °C-annealed selenized PDs and those of the PDs reported by other groups. [8,[38][39][40][41][42][43][44][45][46] For comparison, the key parameters (e.g., dimension, light intensity, and deposition method) that may affect the response time are given in Table S4, Supporting Information. It is noted that the proposed 250 °C-annealed selenized PDs demonstrated the highest responsivity and the fastest switching performance among the compared Sb 2 Se 3 -based devices.…”

“…Most of the reported Sb 2 Se 3 nanostructures were synthesized using chemical vapor deposition, which is intricate and necessarily uses chemical precursors and requires high reaction temperatures, typically between 300 and 900 °C. [8][9][10] Polycrystalline Sb 2 Se 3 thin films represent an alternative avenue for conductivity enhancement. Polycrystalline Sb 2 Se 3 thin films were prepared using various methods including vapor deposition technology, thermal evaporation, chemical bath technology, and sputtering.…”

Bi2O2Se Nanowire/MoSe2 Mixed-Dimensional Polarization-Sensitive Photodiode with a Nanoscale Ultrafast-Response Channel

“…In general, dimensionality engineering is an effective strategy for regulating the electronic, magnetic, piezoelectric, polarization optical, and catalytic properties. − One-dimensional (1D) nanotubes, nanowires, and nanoribbons possess distinctive characteristics such as edge state, quantum scale effect, and ferromagnetism, which demonstrate their potential in serving as building blocks for spintronics, superconductivity, quantum devices, and so on. For instance, among the transition metal dichalcogenides (TMDs), it has been reported that the magnetic and electronic properties of MoS 2 nanoribbons along the zigzag direction are affected by the applied strain and external electric field in the absence of metal doping .…”