Integrated plasmonic lens photodetector

Abstract

We present a fabricated metal-semiconductor-metal ͑MSM͒ photodetector exhibiting an enhanced photocurrent by integrating a nanoscale metallic grating into its contacts. This serves to increase the incident photon flux about the aperture of the device by guiding incident photons as surface plasmon polaritons. High speed time response data shows that the device responsivity may be increased without sacrificing speed. We demonstrate both a photocurrent enhancement and responsivity increase of about 90% at the design wavelength in comparison to otherwise identical MSM photodetectors without integrated nanoscale gratings. The device retains the MSM advantages of simplicity, planarity, and monolithic integrability.

Impact of Nanograting Phase-Shift on Light Absorption Enhancement in Plasmonics-Based Metal-Semiconductor-Metal Photodetectors

“…Figure 3 illustrates a plasmonic-based MSM-PD structure, which consists of three separate layers, namely, (i) a top layer (metal nanograting), (ii) an unperturbed metal layer (underlayer) containing conventional sub-wavelength apertures, and (iii) a semiconductor (GaAs) substrate. For a metal nanograting with the period of Λ, the wave vector of the excited SPPs (k sp ) is given by [1,[8][9][10][11] …”

“…Based on finite-difference time-domain (FDTD) simulation, results have shown significant enhancement of light absorption through interaction with surface plasmon polaritons (SPPs) for the design of MSM-PDs [1,[5][6][7][8][9][10][11]. In this paper, the FDTD method is used to simulate the light absorption enhancement in a GaAs MSM-PD structure, wherein the metal fingers are structured to form a metal nanograting above an unperturbed part of the metal fingers.…”

“…In recent years, sub-wavelength nanostructured metal nanogratings have been identified as promising candidates for realising high-speed improved sensitivity metal-semiconductor-metal photodetectors (MSM-PDs) [1]. The strong interaction of a nanostructured metal grating with an incident light enables trapping the light through the metal finger slit into the semiconductor substrate, leading to substantial improvement in light absorption, and opening the way for a wide range of potential applications, such as optical fiber communications, high-speed chip-to-chip interconnects, and high-speed sampling [2,3].…”

Nanoantenna coupled UV subwavelength photodetectors based on GaN

“…A carefully designed nano-antenna positioned on top of a photodetector, which is smaller in size than the wavelength of the incident light, can be used to collect more photons. There are many experimental and computational examples reported for such devices from the near-IR to visible spectrum [2][3][4][5][6][7][8]. However, there is not many research reported on plasmonic structures in the UV region.…”

Integrated colloidal quantum dot photodetectors with color-tunable plasmonic nanofocusing lenses

“…[11][12][13] Plasmonic structures for the enhancement of absorption and the concentration of light into nanoscale volumes have been studied theoretically [14][15][16] and experimentally. 17,18 Dipole antennas have been demonstrated to enhance the optical cross sections of Ge nanophotodetectors. 19 Of particular practical interest is the use of a plasmonic bull's eye structure (BES), that is, a concentric plasmonic grating surrounding a nanohole aperture, 20,21 as such a structure can capture light from a large area and concentrate it into a nanoscale aperture.…”