Transparent Conductive Oxide Film for Conductivity-Transparency Balance
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Solution Overview
Problem
Current transparent conducting materials face limitations in achieving high electrical conductivity while maintaining transparency, due to antagonistic dependencies between electrical conductivity and optical transmission, and are constrained by intrinsic carrier density and effective mass, leading to suboptimal Haacke figure of merit and practical challenges such as toxicity and cost in production.
Innovation Solution
A film structure comprising a transparent conductive oxide layer, a wide-bandgap semiconductor oxide layer, and an interface layer with controlled doping and composition, allowing for enhanced carrier mobility and conductivity while maintaining transparency, achieved through pulsed laser deposition and careful layer engineering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heavily doped wide band gap semiconductors are used to increase electrical conductivity, then electrical conductivity is improved, but optical transmission deteriorates due to increased free carrier reflection
Solution Approach 1:
The patent changes the fundamental parameters of the material system by transitioning from conventional wide band gap semiconductors to correlated metal oxides. This involves changing the electronic structure parameters (electron correlation strength, effective mass) to achieve a plasma frequency in the near-infrared region, thereby resolving the contradiction between electrical conductivity and optical transmission in the visible range.
Solution Approach 2:
The patent employs composite material strategies by combining correlated metal oxides with specific doping elements and using heterostructure interfaces (such as LAO/STO) to achieve synergistic effects. The composite approach allows tuning of both electrical and optical properties independently, enabling high conductivity while maintaining transparency.
2Reliability
If intrinsic carrier doping is used to improve electrical conductivity, then carrier mobility is improved, but manufacturing complexity increases due to precise growth requirements
Solution Approach 1:
The patent utilizes self-service mechanisms by employing intrinsic carrier doping through interface engineering and defect control rather than external dopant addition. The material system self-regulates carrier concentration through interface polarization and oxygen vacancy formation, eliminating the need for complex dopant diffusion processes and precise chemical doping control.
Solution Approach 2:
The patent applies preliminary action by pre-engineering the interface structure and composition before device operation. The correlated metal oxide layers are deposited with specific stoichiometries and interface configurations that pre-establish the desired carrier concentration and mobility characteristics, avoiding the need for post-growth doping adjustments.
3Reliability
If conventional metals are used to achieve high electrical conductivity, then electrical conductivity is improved, but optical transmission deteriorates due to free carrier reflection in the visible spectrum
Solution Approach 1:
The patent fundamentally changes the material parameters by using correlated metal oxides instead of conventional metals. The key parameter change is the plasma frequency position, which is shifted from the visible to the near-infrared region through increased effective mass due to electron correlation effects. This allows the material to maintain metallic conductivity while being transparent in the visible range.
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 solution significantly improves the Haacke figure of merit, enabling higher electrical conductivity and transparency by harnessing intrinsic charge transfer and electron correlation, outperforming traditional materials and reducing the need for toxic dopants and expensive substrates.
Implementation Method 1
achieved through pulsed laser deposition and careful layer engineering
Implementation Method 2
the ionic polar discontinuity generates a shift in electronic charge resulting in the formation of a high mobility 2D electron gas
Implementation Method 3
Electronic correlation refers to electrostatic interactions between electrons causing a change in the effective carrier mass
Data Source
AI summary
A film comprising a set of layers including a first layer, a third layer and a second layer therebetween is described. The first layer comprises and/or is a transparent conductive oxide, TCO, having a formula: A1B1O3-δ1; The third layer comprises and/or is a transparent wide-bandgap semiconductor oxide having a formula: A3B303-δ3; The second layer comprises and/or is an oxide layer having a formula: A1αA31-αB1O3-δ2 or A1αA31-αB3O3-δ2 or A3B1βB31-βO3-δ2 or A1αA31-αB1βB31-βO3-δ2; wherein 0<α, β<1, −0.5≤δ1, δ2, δ3≤0.5.