Self-driven highly responsive p-n junction InSe heterostructure near-infrared light detector

Abstract

Photodetectors converting light signals into detectable photocurrents are ubiquitously in use today. To improve the compactness and performance of next-generation devices and systems, low dimensional materials provide rich physics to engineering the light–matter interaction. Photodetectors based on two-dimensional (2D) material van der Waals heterostructures have shown high responsivity and compact integration capability, mainly in the visible range due to their intrinsic bandgap. The spectral region of near-infrared (NIR) is technologically important, featuring many data communication and sensing applications. While some initial NIR 2D material-based detectors have emerged, demonstrations of doping-junction-based 2D material photodetectors with the capability to harness the charge-separation photovoltaic effect are yet outstanding. Here, we demonstrate a 2D p-n van der Waals heterojunction photodetector constructed by vertically stacking p-type and n-type indium selenide (InSe) flakes. This heterojunction charge-separation-based photodetector shows a threefold enhancement in responsivity in the NIR spectral region (980 nm) as compared to photoconductor detectors based on p- or n-only doped InSe. We show that this junction device exhibits self-powered photodetection operation, exhibits few pA-low dark currents, and is about 3–4 orders of magnitude more efficient than the state-of-the-art foundry-based devices. Such capability opens doors for low noise and low photon flux photodetectors that do not rely on external gain. We further demonstrate millisecond response rates in this sensitive zero-bias voltage regime. Such sensitive photodetection capability in the technologically relevant NIR wavelength region at low form factors holds promise for several applications including wearable biosensors, three-dimensional (3D) sensing, and remote gas sensing.

Free-space optical multiplexed orbital angular momentum beam identification system using Fourier optical convolutional layer based on 4f system

“…Free-space optical communication (FSOC) uses optical wavelength (from ultraviolet to infrared) to achieve data transmission through the atmosphere without the requirement of a physical communication link. [1][2][3][4][5][6][7][8][9][10][11] By leveraging the advantage of wider spectrum range in optical bands and compact spatial confinement from a laser beam, FSOC has already provided the ability to cater for high-capacity optical data transmission demand such as using wavelength division multiplexing (WDM) in the Tb/s regime. 12 Meanwhile, confined beam divergence guarantees the security of the communication link to a higher level since a third-party detector could intercept the transmitting beam only when it is placed close to the FSOC path.…”

“…[52][53][54][55][56][57] Learning-based Imaging and focusing through scattering medium, computer-generated holography based on machine learning have been studied. [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75] In FSOC, Timothy Doster and Abbie T. Watnik firstly introduced new method to detect the active OAM modes in a transmission link by utilizing convolutional neural network (CNN) [1]. Qinghua Tian et al proposed a novel turbo-coded 16-ary orbital angular momentum-shift keying -free space optical (OAM-SK-FSO) communication system combining a CNN based adaptive demodulator under strong AT for the first time.…”

30 GHz plasmonic slot MoTe2 photodetector integrated with silicon photonic circuits at telecom wavelength

“…1.b), [31][32][33] which have the potential to enable novel optoelectronic devices with improved performance, such as modulators, lasers, solar cells, and photodetectors. 27,[34][35][36][37][38] High-frequency response photodetector plays an important role in a vast range of applications such as bioimaging, thermal imaging, chemical analysis, medical imaging, telecommunication, and on-chip optical computing.(Fig. 1.a) [39][40][41][42][43][44] Compared to traditional III-V and II-IV materials, 2D materials have several advantages, such as no lattice structures alignment needed, ease of integration to different substrates, low cost, nanometer thickness, and simple fabrication process.…”

Design and testing of silicon photonic 4F system for convolutional neural networks

“…Larger channel number is possible by implementing smaller modulators, 44,69,70 and photodetectors, [71][72][73] for example exploiting novel materials such as ITO, 74 Lithium Niobate, [75][76][77][78][79][80] graphene, 81,82 and so on. 83 Moreover, the focal length is closely related to the input channels in a direct way. The input and output waveguides have to be tapered to permit the maximum overlapping between the incoming wave and the optical mode.…”

“…As the first implementation, the number of input and output channels has been limited to 16, to permit testing the transfer function in a limited footprint. Larger channel number is possible by implementing smaller modulators,44,69,70 and photodetectors,[71][72][73] for example exploiting novel materials such as ITO,74 Lithium Niobate,[75][76][77][78][79][80] graphene,81,82 and so on 83. Moreover, the focal length is closely related to the input channels in a direct way.…”