Transparent Electrode Structure for High-Frequency Photodetection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed optical communication using visible light results in significantly lowered reception sensitivity of Si semiconductor photodiodes at frequencies above several tens of GHz, necessitating an efficient means to transmit and extract optical signals using magnetic elements.
Innovation Solution
An electrode structure featuring a metal film with an opening for a transparent conductive film, which is electronically connected to a magnetic element with ferromagnetic layers and a spacer layer, allowing efficient optical signal transmission and electric signal extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Si semiconductor photodiode is used for visible light optical communication, then the device can be manufactured with existing technology, but the reception sensitivity is remarkably lowered when the frequency becomes several tens of GHz or more
Solution Approach 1:
The patent changes the material parameter from conventional Si semiconductor to magnetic element (with ferromagnetic layers and spacer layer), enabling the photodetector to maintain high reception sensitivity at high frequencies (several tens of GHz or more) where traditional Si photodiodes fail
Solution Approach 2:
The patent employs a composite structure consisting of multiple ferromagnetic layers separated by a spacer layer, creating a magnetic element that functions as a photodetector. This composite material approach enables high-frequency response while maintaining manufacturing feasibility
2Reliability
If a magnetic element with ferromagnetic layers and spacer layer is used to respond to high-frequency optical signals, then the reception sensitivity at high frequency is improved, but a new structure is required for efficient optical signal transmission and electric signal extraction
Solution Approach 1:
The transparent conductive film serves multiple functions simultaneously: it acts as an electrode for electric signal extraction and as an optical window for light transmission to the magnetic element. This multi-functionality reduces the need for separate components, simplifying the overall device structure despite the advanced material requirements
Solution Approach 2:
The transparent conductive film acts as an intermediary between the optical signal and the magnetic element, allowing optical signals to pass through to reach the magnetic element while also providing an electrical connection for signal extraction. This mediator approach resolves the conflict between optical transparency and electrical conductivity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables efficient transmission of optical signals and extraction of electric signals from the magnetic element, enhancing the reception sensitivity for high-frequency optical signals.
Implementation Method 1
a transparent conductive film disposed in the opening, wherein the transparent conductive film is electronically connected to an element and overlaps with the element as viewed in a plan view in a thickness direction of the transparent conductive film... configured to be irradiated with light
Data Source
AI summary
An electrode structure includes: a metal film with an opening formed in a part of the metal film; and a transparent conductive film disposed in the opening, wherein the transparent conductive film is electronically connected to an element and overlaps with the element as viewed in a plan view in a thickness direction of the transparent conductive film.