Piezoelectric Element Oxide Layer Reduces Leak Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piezoelectric elements face challenges in reducing leak current while maintaining good piezoelectric characteristics, as dielectric breakdown often occurs when attempting to minimize leak current.
Innovation Solution
A piezoelectric element is designed with a first electrode, an oxide layer, a piezoelectric layer containing potassium, sodium, and niobium, and a second electrode. The oxide layer forms a pn junction with the piezoelectric layer, allowing for a significant reduction in leak current when a specific potential difference is applied, with a current density difference of 10,000 times or more between forward and reverse bias configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If elements of the piezoelectric material are substituted to reduce leak current, then leak current is reduced, but dielectric breakdown is likely to occur causing damage to piezoelectric characteristics
Solution Approach 1:
An oxide layer is introduced as an intermediary between the electrode and the piezoelectric layer. This oxide layer forms a pn junction with the piezoelectric layer, acting as a mediator that controls current flow. The pn junction structure allows the oxide layer to block leak current while maintaining the piezoelectric characteristics of the underlying layer, thus resolving the contradiction between reducing leak current and preserving piezoelectric performance.
Solution Approach 2:
The device employs a composite structure combining the oxide layer and the piezoelectric layer containing potassium, sodium, and niobium. This composite material approach allows the oxide layer to provide electrical insulation and current control, while the piezoelectric layer maintains the desired piezoelectric properties. The combination enables simultaneous achievement of low leak current and good piezoelectric characteristics.
2Object-generated harmful factors
If the oxide layer forms a pn junction with the piezoelectric layer, then leak current is significantly reduced, but the structure becomes more complex
Solution Approach 1:
The invention utilizes parameter changes in the oxide layer, specifically forming a pn junction by controlling the oxidation state and composition of the oxide layer. By adjusting these parameters, the oxide layer achieves effective current blocking without requiring complex structural modifications. The pn junction formation is achieved through controlled material properties rather than complex geometry, thus reducing the increase in device complexity.
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 proposed solution effectively reduces leak current while preventing dielectric breakdown, enabling the piezoelectric element to maintain high efficiency and stability even under high voltage applications.
Implementation Method 1
The oxide layer forms a pn junction with the piezoelectric layer, allowing for a significant reduction in leak current when a specific potential difference is applied
Implementation Method 2
A piezoelectric element is used in various fields such as a liquid ejection head of an inkjet printer
Data Source
AI summary
A piezoelectric element includes: a first electrode; an oxide layer formed on the first electrode; a piezoelectric layer formed on the oxide layer and containing potassium, sodium, and niobium; and a second electrode formed on the piezoelectric layer. When a potential difference of 10 V is applied between the first electrode and the second electrode, a current density of a leak current differs by 10,000 times or more between a case in which the first electrode is set at a high potential and a case in which the second electrode is set at a high potential.