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

Abstract

of polarization states: i) Natural light, the vibrational plane of which is not fixed. The electric vectors of natural light are axisymmetric, evenly distributed in all directions and synchronously vibrating. ii) Complete polarized light can be subdivided into linearly polarized light, elliptically polarized light, and circularly polarized light. Linearly polarized light has a fixed vibrational plane. The vibrational track of its electric vector is a straight line during propagation. Elliptically polarized light, similarly, the terminal trajectory that the electric vector vibrates is an ellipse. The plane of the ellipse is perpendicular to the propagative direction of light. And the electric vector rotates constantly, the magnitude and direction of which change regularly with time. When facing the direction light propagates, if the end of the electric vector travels counterclockwise, it is a right-handed circular polarization state; if clockwise, it is a left-handed circular polarization state. Circularly polarized light is a special case of elliptically polarized light. iii) Partially polarized light, the vibration of the electric vector has a comparative advantage in a certain direction. Simply, it is the superposition of natural light and complete polarized light. Because of that common characteristic of light, the polarization state of light provides a new degree of freedom in detection and application. [18,19] Early studies of the polarization-sensitive photodetectors mainly focus on the macroscopic anisotropy, which requires complex technologies for the patterning and aligning process. [20][21][22] Anisotropic low-dimensional materials have low-symmetry crystal structures including orthorhombic, monoclinic, and triclinic so that they have intrinsic anisotropic properties [23][24][25] obtaining highly polarization sensitivity for photodetectors. [26,27] Fortunately, low-dimensional materials are emerging due to their large families, [28][29][30][31][32] fascinating photo electric characteristics, [28,[32][33][34] and naturally microscopic anisotropy among most of them. [23] From early on, the pioneering work has been done on BP-based polarization-sensitive photodetectors, which advance the development of anisotropic systems in this application. [35] According to the diversified evolution of element types, apart from black phosphorus, [36][37][38][39][40] some monoelemental 2D materials with anisotropy like black arsenic, [41,42] antimonene, [43,44] borophene, [45,46] and tellurene [47,48] have been discovered and studied. Meanwhile, a mass of anisotropic binaries have sprung up typically including

On-chip mid-infrared photothermoelectric detectors for full-Stokes detection

“…However, such bulky and complicated optical systems by using free-space polarizer have intrinsic drawbacks such as limited speed, limited accuracy, and incomplete polarization state detection 9 . Recent advances in low-dimensional nanophotonic technologies have unveiled fascinating approaches to develop the next-generation polarimeters 10 , 11 . As a potential candidate for the next-generation compact polarimeters, on-chip polarization-sensitive photodetectors have been widely studied recently owing to their advantages including high level of miniaturization and ultrahigh-density integration.…”

Giant in-plane optical and electronic anisotropy of tellurene: a quantitative exploration

“…S8c, † and the measured maximum reaches 1.38 at a wavelength of 785 nm. The giant measured and calculated birefringence and dichroism make the tellurene nanosheet a promising candidate for designing polarization-sensitive optoelectronic devices, such as wave plates, 45,46 polarization-sensitive photodetectors, 47,48 etc. We also investigated the thickness dependence of Δn and Δk with the help of first-principles calculations, as shown in Fig.…”

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

“…[14][15][16][17] Indeed, the polarization sensitivity of 1D nanostructures mainly originates from anisotropic morphology, because the diameter is much smaller than that of the optical wavelengths, but the length is considerably larger. [9] The polarized photocurrent always achieves its maximum when the polarization direction of incident light is parallel to the long axis of 1D nanostructures. [6,14,15] The influence of crystal structure anisotropy and multi-faced features on the polarizationsensitive PDs based on 1D nanostructures will be overshadowed.…”

“…[7,8] Low-dimensional anisotropic materials with polarization characteristics are considered as promising candidates to overcome these issues owing to their tiny size, rich structures, strong light-matter interactions, and excellent compatibility. [1,9] Generally, low-dimensional anisotropic materials as an active layer in constructing polarization-sensitive PDs include 2D and 1D materials. The emerging 2D materials such as black phosphorus, GeSe 2 , ReS 2 , and PdSe 2 greatly boost the detection of polarization light owing to their intrinsic anisotropic crystal structures and high optical sensitivity.…”