Light-Emitting Waveguide Structure for Higher Projector Emittance
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Solution Overview
Problem
Current light emitting devices, such as semiconductor lasers used in projectors, face challenges in improving light emittance efficiency due to limitations in the design of semiconductor materials and structures.
Innovation Solution
A light emitting device is designed with a light emitting waveguide layer comprising indirect transition semiconductors forming a pn junction, where an electrode injects electric current to generate light with energy less than the band gap energy, causing the light to resonate and be emitted in a specific direction through an optical portion, enhancing emittance efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional semiconductor laser structures are used, then device simplicity is maintained, but light emittance efficiency is insufficient
Solution Approach 1:
The light emitting waveguide layer is segmented into multiple semiconductor portions (first, second, third portions) with different conductive types arranged in alternating layers. This segmentation creates multiple pn junctions within a single waveguide layer, enabling improved light emittance efficiency through structured carrier injection and recombination zones while maintaining manageable device complexity through systematic layering.
Solution Approach 2:
Different semiconductor portions are assigned different conductive types (n-type, p-type) and positions within the waveguide layer to create localized functional zones. The first semiconductor portion has n-type conductivity, the second has p-type conductivity, and the third has n-type conductivity, creating optimized local conditions for carrier injection, recombination, and light generation at specific pn junction interfaces.
2Use of energy by moving object
If direct band gap semiconductors are used, then light generation efficiency is high, but the patent specifically employs indirect transition semiconductors to achieve specific wavelength emission
Solution Approach 1:
The patent utilizes indirect transition semiconductors (such as silicon, silicon carbide, or gallium phosphide) that have different band gap energies and emission characteristics compared to direct band gap semiconductors. By carefully selecting and combining different indirect transition semiconductor materials with specific band gap energies, the invention optimizes energy conversion to light while achieving desired emission wavelengths, managing the inherent energy loss through material parameter optimization.
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 improves light emittance efficiency by reducing losses and protecting the light emitting waveguide layer, allowing for the emission of infrared, visible, or red light, making it suitable for use in projectors.
Implementation Method 1
a light emitting waveguide layer including a first semiconductor portion being configured by an indirect transition semiconductor and a second semiconductor portion being configured by an indirect transition semiconductor
Implementation Method 2
the light emitting waveguide layer generates, at the pn junction, light having an energy smaller than a band gap energy of the semiconductors constituting the first semiconductor portion and the second semiconductor portion
Implementation Method 3
causes the light being generated to resonate in the first direction
Implementation Method 4
the light emitting waveguide layer has a longitudinal direction in a first direction, the light emitting waveguide layer generates, at the pn junction, light
Implementation Method 5
the optical portion emits the resonating light to a second direction intersecting with the first direction
Data Source
AI summary
A light emitting device includes a light emitting waveguide layer including a first semiconductor portion and a second semiconductor portion having a conductive type different from the first semiconductor portion, and forming a pn junction with the first semiconductor portion, an electrode being provided to the second semiconductor portion on a side opposite to the first semiconductor portion and injecting an electric current into the pn junction, and at least one optical portion, wherein the light emitting waveguide layer has a longitudinal direction in a first direction, the light emitting waveguide layer generates, at the pn junction, light having an energy smaller than a band gap energy of the semiconductors constituting the first semiconductor portion and the second semiconductor portion, and causes the light being generated to resonate in the first direction, and the optical portion emits the resonating light to a second direction intersecting with the first direction.