Quantum Dot Film Gradient Refractive Index Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Quantum dot display devices have high power consumption due to low light extraction efficiency, which is attributed to the ineffective transmission and reflection of light within the quantum dot film layers.
Innovation Solution
A quantum dot film with multiple layers having refractive indices that gradually increase along the thickness direction, where each layer has a varying quantum dot concentration and base material, enhancing light extraction efficiency by converting transmitting-backward light into transmitting-forward light through total reflection at interfaces between layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a quantum dot film with single layer or uniform structure is used, then the device structure is simple, but the light extraction efficiency is low leading to high power consumption
Solution Approach 1:
The quantum dot film is divided into multiple layers with different refractive indices. Each layer contains quantum dots with specific concentration ranges, creating a gradient structure that segmentally handles light transmission and conversion at different depths, thereby improving overall light extraction efficiency
Solution Approach 2:
Different layers of the quantum dot film are assigned different local properties including varying refractive indices (1.4-1.7), different quantum dot concentrations (5-20% in first layer, 15-30% in second layer, 25-40% in third layer), and different base materials. This local differentiation optimizes light interaction at each depth level
2Use of energy by moving object
If quantum dot concentration is increased to improve light conversion, then light extraction efficiency improves, but light transmittance decreases
Solution Approach 1:
Instead of increasing quantum dot concentration uniformly in a single layer, the invention distributes quantum dots across multiple layers with varying concentrations. This dimensional approach allows light to undergo multiple conversion opportunities at different depths without excessive absorption at any single interface, balancing conversion efficiency with transmittance
Solution Approach 2:
The invention systematically varies key parameters including quantum dot concentration (gradually increasing from 5-20% to 25-40% across layers), refractive index (1.4 to 1.7), and base material composition. These parameter changes create optimal conditions for light extraction while maintaining adequate transmittance
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
Improves light extraction efficiency, reducing power consumption in quantum dot display devices by effectively utilizing quantum dot layers with varying refractive indices and concentrations to enhance light conversion and transmission.
Implementation Method 1
enhancing light extraction efficiency by converting transmitting-backward light into transmitting-forward light through total reflection at interfaces between layers
Data Source
AI summary
The present disclosure provides a quantum dot film including a plurality of quantum dot material layers arranged in stack, the plurality of quantum dot material layers having refractive indices gradually ascending along a thickness direction of the quantum dot film. The present disclosure further provides a color filter layer and a display device.