MoO3 Hole Injection Layer for Organic Devices
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Solution Overview
Problem
Existing organic electroluminescent devices and solar cells face limitations in efficiency and light transmissivity due to the use of V2O5, which is toxic and has low transparency, particularly in the sputtering process, leading to restricted thickness and performance issues.
Innovation Solution
The use of molybdenum trioxide (MoO3) as a charge transfer complex with organic hole-transporting compounds to form a radical cation state, enhancing charge transfer and reducing energy barriers, while offering better safety and light transmissivity, is employed in the device structure, including as a hole injection layer, interfacial layer, and damage reduction layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If V2O5 is used as a charge transfer complex with organic hole-transporting compounds, then charge transfer is enhanced and hole transfer is improved, but light transmissivity decreases and toxicity increases
Solution Approach 1:
The patent changes the material parameter from V2O5 to MoO3, which has different physical and chemical properties. MoO3 provides comparable charge transfer enhancement while offering superior light transmissivity and reduced toxicity, thus resolving the contradiction between charge transfer efficiency and harmful factors
Solution Approach 2:
The patent creates a composite material system consisting of MoO3 combined with organic hole-transporting compounds. This composite forms a charge transfer complex that maintains the beneficial charge transfer properties while eliminating the harmful effects associated with V2O5, achieving both high reliability and reduced harmful factors
2Reliability
If the thickness of the MoO3 layer is increased to improve charge transfer, then hole injection efficiency is enhanced, but light transmissivity decreases
Solution Approach 1:
The patent optimizes the thickness parameter of the MoO3 layer to achieve a balance between charge transfer efficiency and light transmissivity. By controlling the thickness within a specific range, the patent maintains effective hole injection while preserving the superior optical properties of MoO3, resolving the contradiction between these two parameters
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
MoO3 improves the efficiency and transparency of organic devices by forming a charge transfer complex that enhances hole transfer and reduces resistivity, allowing for higher efficiency and safer operation compared to V2O5, with applications in multi-photon emission EL devices and tandem connection solar cells.
Implementation Method 1
a charge transfer complex formed upon contact of an organic hole-transporting compound and molybdenum trioxide via a manner of lamination or mixing thereof, so that the organic hole-transporting compound is in a state of radical cation
Data Source
AI summary
An organic device, including an organic compound having charge-transporting ability (i.e., transporting holes and/or electrons) and/or including organic light emissive molecules capable of emitting at least one of fluorescent light or phosphorescent light, has a charge transfer complex-contained layer including a charge transfer complex formed upon contact of an organic hole-transporting compound and molybdenum trioxide via a manner of lamination or mixing thereof, so that the organic hole-transporting compound is in a state of radical cation (i.e., positively charged species) in the charge transfer complex-contained layer.