Core-Shell Semiconductor Nanoparticles with Optimized Molar Ratios
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Solution Overview
Problem
The synthesis of core shell particles with Group 13-15 (III-V) semiconductor core and shell structures faces challenges in achieving high luminous efficacy and narrow luminous half-width due to variability in synthesis conditions, particularly the molar ratio of Group 13 (III) to Group 15 (V) elements.
Innovation Solution
A core shell particle configuration is developed where the molar ratio of Group 13 (III) to Group 15 (V) elements is set greater than 2.2, with a multilayer shell structure, using X-ray photoelectron spectroscopy analysis, to enhance luminous efficacy and narrow the luminous half-width, and the method involves specific raw materials and synthesis steps to form the core, first shell, and second shell layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional synthesis methods are used for core shell particles, then the synthesis process can be performed with standard conditions, but the luminous efficacy varies greatly and the luminous half-width becomes broad
Solution Approach 1:
The patent applies parameter changes by optimizing the molar ratio of Group 13 to Group 15 elements to greater than 2.2, controlling particle diameter within 2-50 nm, and adjusting shell thickness ratios. These parameter optimizations directly resolve the contradiction by achieving high luminous efficacy (greater than 50%) and narrow luminous half-width (less than 50 nm) simultaneously, eliminating the variability observed in conventional synthesis methods.
2Reliability
If the molar ratio of Group 13 to Group 15 elements is not optimized, then the synthesis process is simpler, but the luminous efficacy is low and the luminous half-width is broad
Solution Approach 1:
The patent establishes specific parameter ranges including molar ratio greater than 2.2, particle diameter of 2-50 nm, and shell thickness ratio between 0.1-2.0. These defined parameters provide clear synthesis guidelines that improve luminous efficacy to greater than 50% while maintaining manageable synthesis complexity through standardized control ranges.
3Reliability
If quantum dots containing Cd or Pb elements are used, then high luminous efficacy can be achieved, but the particles contain hazardous substances regulated by RoHS
Solution Approach 1:
The patent replaces hazardous Cd and Pb elements with Group 13-15 semiconductor materials (such as InP, GaP, InAs) while maintaining high luminous efficacy through optimized molar ratios greater than 2.2 and controlled particle diameters of 2-50 nm. This substitution eliminates RoHS-regulated hazardous substances while achieving luminous efficacy greater than 50%, resolving the contradiction between performance and environmental compliance.
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 approach results in increased luminous efficacy and reduced luminous half-width, with the molar ratio range of 2.5 to 5.0 providing optimal results, demonstrating improved light emission characteristics.
Implementation Method 1
a band gap typically becomes larger as the particle diameter of particles having such a nanoscale decreases due to so-called quantum size effects, and the particles exhibit light emission in a short wavelength range such as an ultraviolet region or a near ultraviolet region
Implementation Method 2
the molar ratio of the Group 13 (III) element contained in the core to the Group 15 (V) element contained in the entirety of the core shell particle, which is acquired using X-ray photoelectron spectroscopy analysis
Data Source
AI summary
An object of the present invention is to provide core shell particle having high luminous efficacy and a narrow luminous half-width; a method of producing the same, and a film obtained by using core shell particles. The core shell particle of the present invention includes a core which contains a Group III element and a Group V element; a first shell which covers at least a part of a surface of the core; and a second shell which covers at least a part of the first shell. The molar ratio of the Group III element contained in the core to the Group V element contained in the entirety of the core shell particle, which is acquired from X-ray photoelectron spectroscopy analysis, is greater than 2.2.