Warping effect-induced optical absorbance increment of topological insulator films for THz photodetectors with high signal-to-noise ratio.
نویسندگان
چکیده
Strong optical absorbance makes topological insulator (TI) surfaces a promising high-performance photodetector in the terahertz (THz) to infrared frequency range. Here, we study the optical absorbance of more realistic TI films with hexagonal warping effect using the Fermi's golden rules. It was found that when the warping term is λ ≠ 0, the absorbance is no longer a universal value as that of graphene or ideal Dirac cone, but increases monotonously with the photon energy. The increment is positively correlated with the parameter λ/vF(3) where vF is the Fermi velocity. The relative signal-to-noise ratio (SNR) of the TI film working as a photoresistor-type photodetector is significantly enhanced by the warping effect-induced absorbance increment. These investigations provide useful information for developing TI-based photodetectors with high SNR in the range of THz to infrared frequency.
منابع مشابه
The Department of Electrical Engineering
Materials with Dirac-type electronic band structure have recently drawn much interest. These materials revealed unique electrical, thermal and optical properties, which can be potentially used in future highspeed electronics. In this dissertation research, I investigate on two different classes of Dirac materials: graphene and topological insulators of the bismuth telluride (Bi2Te3) family. The...
متن کاملAnomalous Photoelectric Effect of a Polycrystalline Topological Insulator Film
A topological insulator represents a new state of quantum matter that possesses an insulating bulk band gap as well as a spin-momentum-locked Dirac cone on the surface that is protected by time-reversal symmetry. Photon-dressed surface states and light-induced surface photocurrents have been observed in topological insulators. Here, we report experimental observations of an anomalous photoelect...
متن کاملChapter 2 . High - Frequency InAIAs / InGaAs Metal - Insulator - Doped Semiconductor Field - Effect Transistors ( MIDFETs ) for Telecommunications
InAlAs/InGaAs Modulation-Doped Field-Effect Transistors (MODFETs) on InP have recently emerged as an optimum choice for a variety of microwave and photonics applications. This is because the outstanding transport properties of InGaAs have yielded devices with very low-noise and high-frequency characteristics. Unfortunately, the low breakdown voltage of InAlAs/InGaAs MODFETs on InP (typically le...
متن کاملImproved Sensitivity MEMS Cantilever Sensor for Terahertz Photoacoustic Spectroscopy
In this paper, a microelectromechanical system (MEMS) cantilever sensor was designed, modeled and fabricated to measure the terahertz (THz) radiation induced photoacoustic (PA) response of gases under low vacuum conditions. This work vastly improves cantilever sensitivity over previous efforts, by reducing internal beam stresses, minimizing out of plane beam curvature and optimizing beam dampin...
متن کاملMetal-Insulator-Semiconductor Photodetectors
The major radiation of the sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Nanoscale
دوره 6 7 شماره
صفحات -
تاریخ انتشار 2014