Monolithic Reflex Coupler Integrating OLED and CMOS Photodetector
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional reflex couplers with inorganic light-emitting diodes and CMOS photodetectors are not monolithically integratable due to differences in materials and processes, leading to hybrid integration challenges, increased fabrication effort, and high costs, especially in high-volume production, particularly in applications requiring high reliability like the automobile industry.
Innovation Solution
Integration of an organic light-emitting diode (OLED) as a top emitter on a CMOS substrate, where the OLED and inorganic photodetector are monolithically integrated, utilizing CMOS structures as electrical insulators and lightguides, allowing for low-temperature deposition and easy integration on silicon substrates, thus enabling a monolithic reflex coupler with reduced fabrication complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional inorganic light-emitting diodes and CMOS photodetectors are used in reflex couplers, then reliable light transmission and detection are achieved, but monolithic integration is prevented due to material and process differences
Solution Approach 1:
The patent merges the light-emitting function and light-detecting function onto a single CMOS substrate by integrating an OLED structure with a photodetector, eliminating the need for separate hybrid integration of inorganic LEDs and CMOS photodetectors. This combining approach resolves the contradiction by achieving monolithic integration while maintaining reliable optical coupling through the shared substrate platform.
Solution Approach 2:
The CMOS substrate serves multiple functions simultaneously: it acts as the structural foundation, provides electrical insulation through its oxide layers, guides light through its layered structure, and hosts both the OLED and photodetector components. This multi-functionality enables monolithic integration without requiring separate specialized substrates for each component.
2Ease of manufacture
If hybrid integration of CMOS photodetectors and inorganic light-emitting diodes is used, then functional reflex couplers are achieved, but fabrication effort and costs increase especially in high-volume production
Solution Approach 1:
The patent combines OLED fabrication processes with standard CMOS manufacturing workflows, allowing both components to be produced on the same substrate using compatible materials and deposition techniques. This merging eliminates the need for separate hybrid assembly steps, reducing fabrication complexity and enabling high-volume production through standardized CMOS manufacturing lines.
3Illumination intensity
If inorganic light-emitting diodes are used, then sufficient light emission is achieved, but integration with CMOS substrates is difficult due to material incompatibility
Solution Approach 1:
The patent transitions from inorganic LED materials to organic OLED materials that can be deposited at lower temperatures and are compatible with CMOS substrate characteristics. This parameter change in material composition allows the light-emitting function to be adapted to the CMOS platform while maintaining sufficient illumination intensity through optimized organic layer structures and deposition parameters.
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 approach allows for high integration efficiency, low current consumption, and the ability to produce reflex couplers on large substrates with reduced chip area, enabling cost-effective and reliable monolithic integration of light sources and detectors on a single silicon substrate, with the flexibility to adapt to various sensor geometries and applications.
Implementation Method 1
an organic light emitter for emitting a light signal
Implementation Method 2
an inorganic photodetector, which has a detector area, wherein the light emitter and the detector area can be coupled optically as a result of radiation returned from an object onto which the light signal impinges
Data Source
AI summary
A reflex coupler has an organic light emitter for generating a light signal and an inorganic photodetector with a detector area. The organic light emitter and the detector area are optically coupled as a result of radiation returned from an object onto which the light signal impinges, and the organic light emitter and the inorganic photodetector are integrated in one device.