Core-Shell Quantum Rod Luminescent Material for Broadband VIS-NIR Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Near-Infrared (NIR) LEDs have a narrow spectral width and high energy loss due to strong reabsorption between phosphors, limiting their sensitivity and flexibility in applications such as non-destructive testing and biomedical imaging.
Innovation Solution
A luminescent material with an ultra-broadband VIS-NIR emitting ability is created using a spherical indium phosphide core, a cadmium selenide spherical shell, and a cadmium sulfide rod-shaped shell, forming a Type II quantum rods structure that enhances emission from visible light to near-infrared, reducing energy loss and improving luminous efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional NIR LEDs with narrow FWHM are used, then device complexity is reduced, but spectral coverage is insufficient leading to low sensitivity
Solution Approach 1:
The patent employs a core-shell quantum dot structure with CdSe/CdS composition, where the core provides strong NIR emission and the shell extends the emission spectrum. This composite material approach achieves ultra-broadband VIS-NIR coverage (450-1000 nm) while maintaining a single-material system rather than mixing multiple phosphors, thus improving spectral coverage without proportionally increasing device complexity
Solution Approach 2:
The patent utilizes quantum confinement effects by precisely controlling the size and composition parameters of the quantum dots. By adjusting the CdSe core size and CdS shell thickness, the emission spectrum can be tuned across the VIS-NIR range. This parameter optimization enables ultra-broadband emission FWHM exceeding 500 nm while keeping the LED structure relatively simple
2Measurement precision
If multiple colored phosphors are mixed to achieve full-spectrum LED, then spectral coverage is improved, but strong reabsorption causes large energy loss and reduced luminous efficiency
Solution Approach 1:
Instead of mixing multiple phosphor materials that suffer from mutual reabsorption, the patent uses a single quantum dot material system (CdSe/CdS) with controlled composition gradients. The core-shell structure enables broadband emission through quantum size effects rather than phosphor mixing, eliminating the reabsorption problem while achieving VIS-NIR spectral coverage
Solution Approach 2:
The patent creates different functional zones within the quantum dot: the CdSe core provides strong absorption and NIR emission, while the CdS shell extends the emission to visible wavelengths and reduces surface defects. This local differentiation of material properties within a single particle achieves broadband emission without the energy loss associated with mixing multiple phosphors
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 luminescent material achieves ultra-broadband fluorescence, overcoming the limitations of narrow spectral width and energy loss in conventional NIR LEDs, enabling improved sensitivity and flexibility in various applications.
Implementation Method 1
the present invention hence can generate ultra-broadband fluorescence from visible light to near-infrared (VIS-NIR)
Data Source
AI summary
The present invention is related to a light emission or a luminescent material and applications thereof. The said material comprises a spherical core, a spherical shell deposited at outer surface of the spherical core, and further a rod shell deposited at outer surface of the spherical shell. The said spherical core comprises Indium phosphide particle with substantially spherical appearance or condition. The said spherical shell comprises Cadmium selenium deposited at outer surface of the spherical core with corresponded spherical appearance or condition. The rod shell comprises cadmium sulfide deposited at outer surface of the spherical shell with its structure extended in lengthwise longer than crosswise to a rod appearance or condition. The luminescent material provided by the present invention has a Type II NCs structure using cadmium selenium as the spherical shell to emit near-infrared light. The present invention provides InP/CdS/CeSe in core/shell/shell structure as luminescent material which has extra-broadband VIS-NIR emitting abilities.