Locally Oxidized Silicon Surface-Plasmon Schottky Detector for Telecom Regime

Abstract

We experimentally demonstrate an on-chip nanoscale silicon surface-plasmon Schottky photodetector based on internal photoemission process and operating at telecom wavelengths. The device is fabricated using a self-aligned approach of local-oxidation of silicon (LOCOS) on silicon on insulator substrate, which provides compatibility with standard complementary metal-oxide semiconductor technology and enables the realization of the photodetector and low-loss bus photonic waveguide at the same fabrication step. Additionally, LOCOS technique allows avoiding lateral misalignment between the silicon surface and the metal layer to form a nanoscale Schottky contact. The fabricated devices showed enhanced detection capability for shorter wavelengths that is attributed to increased probability of the internal photoemission process. We found the responsivity of the nanodetector to be 0.25 and 13.3 mA/W for incident optical wavelengths of 1.55 and 1.31 μm, respectively. The presented device can be integrated with other nanophotonic and nanoplasmonic structures for the realization of monolithic opto-electronic circuitry on-chip.

On-Chip Detection of Radiation Guided by Dielectric-Loaded Plasmonic Waveguides

“…In contrast, under the reverse-bias condition, the current saturates rapidly with the increased applied voltage, reaching a value of around 250 nA. This dark current value is one order of magnitude larger than that reported in the literature 14 , which we attribute to the larger contact interface area used in the present structure. The generation of the photocurrent includes the following processes.…”

Harvesting the loss: surface plasmon-based hot electron photodetection

“…Hot electrons have also played a role in realizing on-chip photodetectors based on silicon with several demonstrations [45,85,87,[118][119][120][121][122][123] over the past several years. Despite the success of using silicon photonics for controlling light emission, propagation, and modulation, the use of silicon as an active absorbing material in the telecommunication band is challenging due its transparency in this regime.…”

“…Internal responsivity of 0.38 and 1.04 mA/W were measured at a wavelength of 1280 nm [120] for gold and aluminum stripes on n-type silicon, respectively. A silicon waveguide-based SPP Schottky photodetector operating at telecom wavelengths has also been developed [45] (Figure 4B). The device was fabricated using a self-aligned approach of local oxidation of silicon (LOCOS) on a silicon on insulator substrate ( Figure 4B).…”

“…In plasmonic metamaterials, the nonradiative decay process will lead to optical absorption in the metal and reduced performance. Although much effort has been devoted to mitigating plasmon nonradiative decay, recent research has uncovered exciting opportunities for harnessing the process [27,34], such as in photothermal heat generation [35,36], photovoltaic devices [27,37], photocatalysis [38][39][40], driving material phase transitions [41,42], photon energy conversion [43], and photodetection [44][45][46][47][48][49][50]. For instance, the decay of hot electrons can lead to the local heating of the plasmonic nanostructures, making them candidates for nanoscale heat sources [35,36] for use in cancer therapy [51] and solar steam generation [52,53].…”

Propagating Surface Plasmon Polaritons: Towards Applications for Remote‐Excitation Surface Catalytic Reactions

“…In addition, due to the high throughput and low energy requirements, a novel application of plasmonics in chemical reactions gains significant attention, as reported in works on dissociation of hydrogen15, 16 and water,17, 18 photochemical19, 20, 21, 22, 23 and plasmon‐driven chemical reactions,24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 etc. SPs excited on the surface of gold or silver can non‐radiatively decay into so‐called hot electrons with a high energy between the Fermi and vacuum energy level 36, 37, 38, 39, 40. The hot electrons could scatter into the absorbed molecule's excited state and then trigger chemical reactions by reducing the activation energy, so‐called plasmonic catalysis 41.…”