Molybdenum Carrier Structure for Surface-Emitting IR-LED Light Extraction
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Solution Overview
Problem
Conventional surface emitting infrared light emitting diodes (IR-LEDs) face significant light absorption issues due to the use of expensive substrates like GaAs, which require complex processing and result in low light extraction efficiency, as photons emitted towards the substrate are largely absorbed.
Innovation Solution
A semiconductor device with a light-emitting film grown on a sacrificial substrate featuring a random textured surface, combined with a mirror system and a conductive molybdenum carrier, where the substrate is removed and replaced with a transparent carrier, and a dielectric film is used to enhance light reflection and extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional substrates like GaAs are used for surface emitting IR-LEDs, then the device can be manufactured with standard processes, but light extraction efficiency is low due to substrate absorption and cost is high
Solution Approach 1:
The device is segmented into distinct functional layers: a sacrificial substrate used only during growth, a light-emitting film, and a transparent carrier substrate. The sacrificial substrate is removed after growth, separating the manufacturing function from the optical function, allowing high efficiency without compromising manufacturability
Solution Approach 2:
The absorbing substrate is extracted and removed from the final device structure. By taking out the GaAs substrate after growth and replacing it with a transparent carrier, the harmful absorption function is eliminated while retaining the benefit of standard semiconductor manufacturing processes
2Ease of manufacture
If conventional flat substrates are used, then manufacturing is simpler, but light extraction efficiency is low due to total internal reflection
Solution Approach 1:
The substrate surface is transformed from flat to randomly textured with curved features. This curvature disrupts total internal reflection by creating varied incident angles for photons, significantly improving light extraction efficiency while the texturing process is compatible with standard semiconductor manufacturing
Solution Approach 2:
The random texturing is applied locally to the substrate surface where light emission occurs, creating regions with enhanced optical properties. This localized modification improves light extraction only where needed without complicating the overall device structure or manufacturing process
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
The random textured surface and mirror system significantly increase the fraction of photons that escape the device, enhancing light extraction efficiency and output power compared to conventional LEDs.
Implementation Method 1
the substrate is provided with a random textured surface... The random textured surface and mirror system significantly increase the fraction of photons that escape the device
Implementation Method 2
combined with a mirror system and a conductive molybdenum carrier, where the substrate is removed and replaced with a transparent carrier, and a dielectric film is used to enhance light reflection and extraction efficiency
Data Source
AI summary
An optoelectronic semiconductor device includes a top contact and a conductive carrier including a metallic molybdenum conductive carrier substrate. A metal layer is deposited on the metallic molybdenum conductive carrier substrate. A light emitting film is disposed between the top contact, a mirror layer and the metallic molybdenum conductive carrier substrate.