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Ekaterina Ponizovskaya Devine

Publications and source records attributed to Ekaterina Ponizovskaya Devine.

6 recordsLinked to original sources
arXiv2024

Simulation of Ge on Si Photodiode with photon-trapping micro-nano holes with -3dB bandwidth of >60 GHz at NIR wavelength

The study proposes an ultra-thin back side illuminated (BSI) and top-illuminated, Ge on Si photodetector (PD), for 1 to 1.4 microns wavelength range. The Ge thickness of 350 nm allows us to achieve high-speed performance at >60 GHz, while the nanostructure at the bottom of the Ge layer helps to increase the optical absorption efficiency to above 80%. The BSI PD allows the PD or PD array wafer to be stacked with an electronic wafer for signal processing and transmission for optical interconnect applications such as short-reach links in data centers. Nano-microhole parameters in randomized composite formation on the bottom layer are optimized with Monte-Carlo molecular dynamics simulations incorporating charge transport to enable wide-spectral, highly efficient, and ultra-fast PDs.

physics.app-ph↗
arXiv2023

Achieving higher photoabsorption than group III-V semiconductors in silicon using photon-trapping surface structures

The photosensitivity of silicon is inherently very low in the visible electromagnetic spectrum, and it drops rapidly beyond 800 nm in near-infrared wavelengths. Herein, we have experimentally demonstrated a technique utilizing photon-trapping surface structures to show a prodigious improvement of photoabsorption in one-micrometer-thin silicon, surpassing the inherent absorption efficiency of gallium arsenide for a broad spectrum. The photon-trapping structures allow the bending of normally incident light by almost ninety degrees to transform into laterally propagating modes along the silicon plane. Consequently, the propagation length of light increases, contributing to more than an order of magnitude improvement in absorption efficiency in photodetectors. This high absorption phenomenon is explained by FDTD analysis, where we show an enhanced photon density of states while substantially reducing the optical group velocity of light compared to silicon without photon-trapping structures, leading to significantly enhanced light-matter interactions. Our simulations also predict an enhanced absorption efficiency of photodetectors designed using 30 and 100-nanometer silicon thin films that are compatible with CMOS electronics. Despite a very thin absorption layer, such photon-trapping structures can enable high-efficiency and high-speed photodetectors needed in ultra-fast computer networks, data communication, and imaging systems with the potential to revolutionize on-chip logic and optoelectronic integration.

physics.optics↗
arXiv2020

Maximizing absorption in photon trapping ultra-fast silicon photodetectors

Silicon photodetectors operating at near-infrared wavelengths with high-speed and high sensitivity are becoming critical for emerging applications, such as Light Detection and Ranging Systems (LIDAR), quantum communications, and medical imaging. However, such photodetectors present a bandwidth-absorption trade-off at those wavelengths that have limited their implementation. Photon trapping structures address this trade-off by enhancing the light-matter interactions, but maximizing their performance remains a challenge due to a multitude of factors influencing their design and fabrication. In this paper, strategies to improve the photon trapping effect while enhancing the speed of operation are investigated. By optimizing the design of photon trapping structures and experimentally integrated them in high-speed photodetectors, a simultaneous broadband absorption efficiency enhancement up to 1000% and a capacitance reduction of more than 50% has been achieved. Such work also allows to present empirical equations to correlate the quantum efficiency of photodetectors with the physical properties of the photon-trapping structures, material characteristics, and limitations of the fabrication technologies. The results obtained, open routes towards designing cost-effective CMOS integrated.

physics.optics↗