We report the frequency response of AlInAsSb/AlInAsSb nBn photodetectors. The 3-dB bandwidth of the devices varies from ∼ 150 MHz to ∼ 700 MHz with different device diameters and saturates with bias voltage immediately after the device turn on. A new equivalent circuit model is developed to explain the frequency behavior of nBn photodetectors. The simulated bandwidth based on the new equivalent circuit model agrees well with the bandwidth and the microwave scattering parameter measurements. The analysis reveals that the limiting factor of the bandwidth of the nBn photodetector is the large diffusion capacitance caused by the minority carrier lifetime and the device area. Additionally, the bandwidth of the nBn photodetector is barely affected by the photocurrent, which is found to be caused by the barrier structure in the nBn photodetector.
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http://dx.doi.org/10.1364/OE.457057 | DOI Listing |
Raising the operating temperature of mid-wavelength infrared detectors is critical for meeting the low size, weight, and power (SWaP) demands of infrared imaging systems. In this work, we report and analyze a high operating temperature (HOT) InAsSb nBn mid-wave infrared (MWIR) focal plane array (FPA) and single element photodetectors with AlAs/AlSb superlattices as the electron barrier. Under an applied bias of -350 mV, the nBn photodetectors demonstrate a dark current density of 2.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, 111 Jiu Long Road, Hefei, 230601, China.
Unipolar barrier architecture is designed to enhance the photodetector's sensitivity by inducing highly asymmetrical barriers, a higher barrier for blocking majority carriers to depressing dark current, and a low minority carrier barrier without impeding the photocurrent flow through the channel. Depressed dark current without block photocurrent is highly desired for uncooled Long-wave infrared (LWIR) photodetection, which can enhance the sensitivity of the photodetector. Here, an excellent unipolar barrier photodetector based on multi-layer (ML) graphene (G) is developed, WSe, and PtSe (G-WSe-PtSe) van der Waals (vdW) heterostructure, in which extremely low dark current of 1.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
Opto-electronic properties and device performance of organic semiconductors are mainly determined by energy levels of their frontier molecular orbitals, e.g. lowest unoccupied molecular orbital (E) and highest occupied molecular orbital (E) in the ground state, first singlet state (E) and first triplet state (E) in the excited state.
View Article and Find Full Text PDFNano Lett
February 2024
Department of Materials Science and Engineering, National University of Singapore, Singapore 117575.
The rapid development of infrared spectroscopy, observational astronomy, and scanning near-field microscopy has been enabled by the emergence of sensitive mid- and far-infrared photodetectors. Superconducting hot-electron bolometers (HEBs), known for their exceptional signal-to-noise ratio and fast photoresponse, play a crucial role in these applications. While superconducting HEBs are traditionally crafted from sputtered thin films such as NbN, the potential of layered van der Waals (vdW) superconductors is untapped at THz frequencies.
View Article and Find Full Text PDFNano Lett
December 2023
Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
With a growing demand for detecting light at the single-photon level in various fields, researchers are focused on optimizing the performance of superconducting single-photon detectors (SSPDs) by using multiple approaches. However, input light coupling for visible light has remained a challenge in the development of efficient SSPDs. To overcome these limitations, we developed a novel system that integrates NbN superconducting microwire photon detectors (SMPDs) with gap-plasmon resonators to improve the photon detection efficiency to 98% while preserving all detector performance features, such as polarization insensitivity.
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