Infrared Sensor EQE Amplification Beyond 1000 nm
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Solution Overview
Problem
Existing infrared sensors struggle to effectively detect light in the near-infrared wavelength spectrum of greater than or equal to about 1000 nm, as silicon photodiodes have limitations in absorbing light beyond this range.
Innovation Solution
The development of a sensor with an external quantum efficiency (EQE) spectrum amplified in the second infrared wavelength region, where the variance of the local maximum EQE value is greater than the variance of the second absorption peak, and the full width at half maximum (FWHM) of the EQE spectrum is narrower than that of the absorption spectrum, allowing for effective detection of light beyond 1000 nm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If silicon photodiodes are used as infrared sensors, then sensitivity in near-infrared wavelength spectrum of less than about 1000 nm is improved, but ability to absorb light in near-infrared wavelength spectrum of greater than or equal to about 1000 nm deteriorates
Solution Approach 1:
The patent changes the material parameter from silicon to organic photodetector materials, which fundamentally alters the absorption characteristics to enable detection in the wavelength range of greater than or equal to about 1000 nm while maintaining sensitivity through optimized material composition and device structure
Solution Approach 2:
The patent employs composite material structures including organic photodetector layers combined with specific electrode configurations and interface engineering to achieve enhanced light absorption in the extended near-infrared region while maintaining device performance
2Measurement precision
If EQE spectrum is amplified in the second infrared wavelength region, then detection capability in extended infrared range is improved, but spectral selectivity may deteriorate due to broader absorption
Solution Approach 1:
The patent applies local quality enhancement by creating a microcavity structure with specific reflectors positioned at predetermined distances from the photodetector, which generates resonant enhancement at targeted wavelengths to improve detection capability while maintaining spectral selectivity through localized optical field concentration
Solution Approach 2:
The patent utilizes dynamic optical resonance effects within the microcavity structure, where the resonant frequency can be tuned by adjusting the cavity dimensions and refractive indices, enabling selective amplification of specific wavelength regions while suppressing others to maintain spectral discrimination
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 solution enhances the light-sensing performance of infrared sensors by amplifying the EQE spectrum in the extended infrared range, achieving improved photoelectric conversion characteristics and broadening the usable range of the sensor.
Implementation Method 1
a light absorbing layer 130 between the first electrode 110 and the second electrode 120
Data Source
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AI summary
A sensor includes a first electrode, a second electrode facing the first electrode, and a light absorbing layer between the first electrode and the second electrode. The light absorbing layer may have a first absorption spectrum having a first absorption peak in a first infrared wavelength region and a second absorption peak in a second infrared wavelength region, the second infrared wavelength region being a longer wavelength region than the first infrared wavelength region. The second absorption spectrum does not at least partially overlap with the first absorption spectrum. The second absorption spectrum may have a lower absorption intensity than the first absorption spectrum. An external quantum efficiency (EQE) spectrum that is amplified in the second infrared wavelength region is exhibited in the sensor.