Monolithic UV LED with Tunable Multiple Quantum Wells
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Solution Overview
Problem
Current UV light sources, such as mercury-vapor lamps, primarily emit single-wavelength spectral outputs, which are inefficient for pathogen inactivation due to limited spectral overlap with DNA absorption peaks, and are not tunable to accommodate different pathogen spectral sensitivities, hindering effective disinfection and curing applications.
Innovation Solution
Development of monolithic semiconductor light-emitting devices with multiple quantum well structures that emit multiple single-wavelength or broadband ultraviolet light across the 210 nm to 400 nm range, allowing for tunable spectral outputs by varying active and barrier layer configurations, materials, and crystal orientations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If single-wavelength UV light sources (low-pressure mercury bulbs) are used, then the spectral output closely matches DNA absorption peak wavelength, but the pathogen inactivation efficiency is limited due to inability to affect aromatic proteins and genetic damage only
Solution Approach 1:
The patent combines multiple quantum well structures with different bandgap energies within a single LED device, enabling simultaneous emission of multiple wavelengths (e.g., 380nm, 395nm, 405nm) to achieve both DNA damage and aromatic protein affection, thereby resolving the contradiction between spectral precision and pathogen inactivation reliability
Solution Approach 2:
The patent changes the emission wavelength parameters by adjusting the composition and thickness of quantum well layers (e.g., varying AlGaN composition ratios), allowing the device to emit multiple discrete wavelengths or broadband spectrum, thus improving pathogen inactivation efficiency while maintaining spectral overlap with DNA absorption
2Adaptability or versatility
If multiple-wavelength UV light sources (medium- and high-pressure mercury bulbs) are used, then the spectral distribution covers broader range including aromatic protein absorption, but the spectral energies do not overlap DNA absorption peak wavelength as much as low-pressure bulbs
Solution Approach 1:
The patent applies local quality by designing specific quantum well regions with tailored compositions to emit at particular wavelengths that simultaneously satisfy both DNA absorption (around 260nm) and aromatic protein absorption (300-400nm) requirements, rather than using a broad unspecific spectrum
Solution Approach 2:
The patent uses composite semiconductor materials (e.g., AlGaN, InGaN quantum wells on GaN substrate) to engineer the bandgap structure, enabling precise control over emission wavelengths to achieve both broad spectral coverage and peak overlap with DNA absorption
3Ease of manufacture
If traditional mercury-vapor lamps are used, then the device structure is simple and cost-effective, but the spectral output is not tunable to accommodate different pathogen spectral sensitivities
Solution Approach 1:
The patent introduces dynamics by making the spectral output tunable through electrical control of quantum well structures, allowing the emission wavelength and bandwidth to be adjusted based on different pathogen targets, thus achieving adaptability while maintaining semiconductor device manufacturing simplicity
Solution Approach 2:
The patent creates a universal UV LED platform that can be configured for different applications (DNA damage, aromatic protein affection, different pathogen types) by adjusting quantum well parameters, making a single device structure serve multiple functions rather than requiring different lamp types
4Adaptability or versatility
If multiple UV LEDs with different spectral outputs are used to achieve multiple-wavelength output, then the spectral coverage is improved, but the device complexity, size, and cost increase significantly
Solution Approach 1:
The patent merges multiple quantum well structures with different emission wavelengths into a single integrated LED chip, eliminating the need for multiple separate LED chips and their associated mounting, wiring, and control circuits, thus reducing device complexity while achieving multiple-wavelength output
Solution Approach 2:
The patent employs nested quantum well structures where multiple active regions with different bandgaps are integrated within a single semiconductor device architecture, allowing compact implementation of multi-wavelength emission without increasing overall device size
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 solution enables more efficient pathogen inactivation and broader applications like curing by providing a customizable and enhanced ultraviolet spectral output, improving disinfection efficiency and versatility compared to traditional UV sources.
Implementation Method 1
Light-emitting diodes and laser diodes are semiconductor light emitters that can generate light upon a sufficient current injection
Implementation Method 2
The light-emitting diode and laser diode are referred to as light-emitting device (LEDs). The wavelength of the light emitted by the LEDs typically depends on the property of the material from which the p-n junction is fabricated
Data Source
AI summary
A monolithic semiconductor light emitting device is described. The device includes an n-type region, a p-type region, an active region of a multiple quantum well structure comprising a plurality of alternating barrier and active layers interposed between the n-type region and the p-type region. The device emits multiple single-wavelength spectral distributions of ultraviolet light each having a peak wavelength of between 210 nm and 400 nm and/or a broadband spectral output having a wavelength of between 210 nm and 400 nm. Methods of making the device and lamps comprising the device are also described.