Nanostructure Optoelectronic Device Sidewall Electrical Contact
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Solution Overview
Problem
Optoelectronic devices face a trade-off between optical transparency and electrical conductivity in their top electrical contacts, limiting their ability to operate effectively over a wide range of wavelengths, particularly in solar cells and LEDs that need to capture energy across the solar spectrum or produce different colors.
Innovation Solution
The use of nanostructure array optoelectronic devices with top sidewall electrical contacts that are physically and electrically connected to the sidewalls of nanostructures, allowing light to enter or leave without passing through the contact, and bi-layer electrical interconnects that enable independent control of photo-active regions, enhancing conductivity while maintaining optical transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the top electrical contact is made from an optically transparent material like ITO, then optical transparency is improved, but electrical conductivity deteriorates
Solution Approach 1:
The electrical contact system is segmented into two separate contacts: a top electrical contact made from optically transparent material (ITO) and a bottom electrical contact made from highly conductive material (metal). This segmentation allows each contact to be optimized for its specific function - the top contact maintains optical transparency while the bottom contact provides superior electrical conductivity, resolving the trade-off between these two properties.
Solution Approach 2:
The invention transitions from a single-plane contact configuration to a three-dimensional configuration where electrical contacts are placed at opposite sides (top and bottom) of the optoelectronic device. This spatial arrangement allows light to enter through the side surfaces of the nanostructures without passing through the electrical contacts, enabling the top contact to be opaque while maintaining device functionality across wide wavelength ranges.
2Reliability
If the top electrical contact is made from an electrically conductive material, then electrical conductivity is improved, but optical transparency deteriorates
Solution Approach 1:
The electrical contact system is segmented into two separate contacts: a top electrical contact made from optically transparent material (ITO) and a bottom electrical contact made from highly conductive material (metal). This segmentation allows each contact to be optimized for its specific function - the top contact maintains optical transparency while the bottom contact provides superior electrical conductivity, resolving the trade-off between these two properties.
3Illumination intensity
If the top electrical contact is made to be optically transparent for a narrow range of wavelengths, then optical transparency in that range is improved, but adaptability to wide wavelength range deteriorates
Solution Approach 1:
The invention transitions from a single-plane contact configuration to a three-dimensional configuration where electrical contacts are placed at opposite sides (top and bottom) of the optoelectronic device. This spatial arrangement allows light to enter through the side surfaces of the nanostructures without passing through the electrical contacts, enabling the top contact to be opaque while maintaining device functionality across wide wavelength ranges.
Solution Approach 2:
The bottom electrical contact serves multiple functions: it provides highly conductive electrical connection and simultaneously serves as an optical window for light entry across a wide wavelength range. This multi-functional design allows the device to operate effectively across the entire solar spectrum without being constrained by the optical properties of the top electrical contact.
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 the operational efficiency of optoelectronic devices by allowing for high electrical conductivity without compromising optical transparency, enabling them to function effectively over a wide range of wavelengths and allowing for independent control of photo-active regions for multi-color operations.
Implementation Method 1
the top electrical contact can be made from a material that has good optical transparency, at least in the relevant range of wavelengths for the device
Implementation Method 2
However, optically transparent materials may not be as electrically conductive as desired
Implementation Method 3
photons absorbed by photo-active regions of the device generate voltage or/and current
Implementation Method 4
Solar cells, otherwise known as photo-voltaic cells, may be operated without applying any bias. Instead, photons absorbed by photo-active regions of the device generate voltage or/and current
Implementation Method 5
bi-layer electrical interconnects that enable independent control of photo-active regions, enhancing conductivity while maintaining optical transparency
Data Source
AI summary
Nanostructure array optoelectronic devices are disclosed. The optoelectronic device may have a top electrical contact that is physically and electrically connected to sidewalls of the array of nanostructures (e.g., nanocolumns). The top electrical contact may be located such that light can enter or leave the nanostructures without passing through the top electrical contact. Therefore, the top electrical contact can be opaque to light having wavelengths that are absorbed or generated by active regions in the nanostructures. The top electrical contact can be made from a material that is highly conductive, as no tradeoff needs to be made between optical transparency and electrical conductivity. The device could be a solar cell, LED, photo-detector, etc.