Silicon Optical Emission via Sol-Gel Elastic Deformation
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Solution Overview
Problem
Indirect band-gap semiconductors, such as silicon, face challenges in achieving efficient optical emission at room temperature due to inherent weak optical emission and damage from strain-based confinement methods, which are impractical for integrating with electronic devices.
Innovation Solution
A sol-gel film with random internal stresses is applied to the surface of silicon, inducing random elastic deformations that enhance the recombination of electrons and holes, leading to substantial optical radiation emission without causing plastic deformation or defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If strain-based confinement methods are used to enhance optical emission from indirect band-gap semiconductors, then optical emission intensity is improved, but the semiconductor material suffers damage from plastic deformation and defects
Solution Approach 1:
A sol-gel layer is introduced as an intermediary between the semiconductor material and the external environment. This layer contains internal stresses that induce elastic deformations in the semiconductor, enhancing optical emission without requiring direct strain application that would cause plastic deformation. The sol-gel layer acts as a mediator that transfers mechanical stress in a controlled manner.
Solution Approach 2:
The invention changes the physical state and stress distribution parameters by using a sol-gel layer with specific internal stress characteristics. The layer is deposited and then annealed at controlled temperatures (400-900°C) to develop the desired internal stress state that induces elastic deformations in the underlying semiconductor without exceeding damage thresholds.
2Illumination intensity
If heterogeneous semiconductor structures are embedded to produce local crystal modifications, then optical emission is enhanced, but device complexity and manufacturing constraints increase
Solution Approach 1:
The invention extracts the stress-inducing function from the semiconductor structure itself and places it in a separate sol-gel layer. Instead of embedding heterogeneous semiconductor structures within the silicon to create local strain, the sol-gel layer is deposited on the surface and provides the strain field from outside, simplifying the overall device structure.
Solution Approach 2:
The invention replaces a mechanical embedding approach (inserting heterogeneous semiconductor structures) with a deposition approach (applying sol-gel layer). This substitution simplifies manufacturing by using standard thin-film deposition techniques rather than complex heteroepitaxial growth and embedding processes.
3Use of energy by moving object
If exciton confinement is implemented in indirect band-gap semiconductors, then optical emission efficiency is improved, but the method is impractical for room temperature operation
Solution Approach 1:
The invention segments the problem by separating the functions of carrier generation, carrier confinement, and radiative recombination. The sol-gel layer specifically addresses the confinement aspect through elastic deformations that create potential wells, while allowing the semiconductor to operate at room temperature for carrier generation and recombination.
Solution Approach 2:
The invention changes the temperature parameter from cryogenic to room temperature operation by using elastic deformations instead of exciton confinement mechanisms that require low temperatures. The sol-gel induced elastic deformations remain effective at room temperature, enabling practical device operation.
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 enables efficient optical emission at room temperature with high external quantum efficiency, compatible with silicon microelectronics fabrication, and is cost-effective for producing silicon-based optical-electronic devices.
Implementation Method 1
The sol-gel film urges or imposes a random distribution of elastic deformations in a region of the silicon that is adjacent to the sol-gel film
Implementation Method 2
electrons and holes in the silicon advantageously recombine, yielding substantial emission of optical radiation from the silicon
Data Source
AI summary
A semiconductor optical emission device comprising a layer of material containing a plurality of stress variations and adhering to a surface of a semiconductor is described. In one embodiment the semiconductor is an indirect band gap semiconductor and is silicon in one aspect, the material of the layer comprises silicon and metal oxides and is prepared by a sol-gel process including thermal annealing in one aspect. The layer urges a plurality of randomly distributed elastic deformations in the semiconductor that substantially enhances the radiative recombination interactions among free carriers in the semiconductor.