Bi-Cu-O-Te Compound Semiconductor for Thermoelectric Conversion
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Solution Overview
Problem
Current compound semiconductors used in solar cells and thermoelectric conversion elements lack long-term electric optical stability, high photoelectric conversion efficiency, and cost-effectiveness, making them unsuitable for practical applications.
Innovation Solution
Development of new compound semiconductors with the formula Bi1-xMxCuwOa-yQ1yTeb-zQ2z, where M is selected from specific elements and Q1 and Q2 are S, Se, or Sb, with specific composition ratios, which are produced by heating mixtures of Bi2O3, Bi, Cu, and Te, and optionally other elements or their oxides, at temperatures between 400 to 570°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional compound semiconductors are used in solar cells and thermoelectric conversion elements, then production costs can be controlled, but long-term electric optical stability and photoelectric conversion efficiency are insufficient
Solution Approach 1:
The patent employs composite material strategy by combining multiple elements (Bi, Cu, O, Te, and dopants like Pb, Sr, Ca, Ba, Nd, Sm, Eu, Ga, In, Tl) to create new compound semiconductors with formula Bi1-xMxCuwOa-yQ1yTeb-zQ2z. These composite materials integrate the advantages of different elements to achieve both high reliability (electric optical stability and photoelectric conversion efficiency) and cost-effectiveness, resolving the contradiction between performance and manufacturing cost.
Solution Approach 2:
The patent applies parameter changes by systematically varying composition parameters (x, w, a, y, b, z) and doping concentrations to optimize material properties. By controlling stoichiometric ratios and introducing controlled deviations from ideal composition, the patent achieves enhanced electric optical stability and photoelectric conversion efficiency while maintaining cost-effectiveness through optimized material usage.
2Productivity
If conventional compound semiconductors are used, then production costs can be managed, but photoelectric conversion efficiency is insufficient
Solution Approach 1:
The patent optimizes photoelectric conversion efficiency by systematically adjusting compositional parameters (x, w, a, y, b, z) and doping levels. Through controlled variation of these parameters, the patent achieves high photoelectric conversion efficiency while maintaining cost-effectiveness by optimizing material composition rather than using expensive materials in excess.
Solution Approach 2:
The patent applies local quality principle by introducing specific dopants at controlled concentrations to enhance photoelectric conversion efficiency at critical locations within the material structure. By strategically placing dopant atoms (Pb, Sr, Ca, Ba, Nd, Sm, Eu, Ga, In, Tl) in the crystal lattice, the patent creates localized regions with optimized electronic properties that boost overall conversion efficiency without proportionally increasing production cost.
3Productivity
If existing thermoelectric conversion materials are used, then device complexity can be kept simple, but energy conversion efficiency is insufficient
Solution Approach 1:
The patent enhances energy conversion efficiency by optimizing thermoelectric parameters (Seebeck coefficient, electric conductivity, thermal conductivity) through controlled composition adjustments. By varying doping concentrations and stoichiometric ratios within the Bi-Cu-O-Te system, the patent achieves high ZT values and improved energy conversion efficiency while maintaining relatively simple device structures.
Solution Approach 2:
The patent applies universality by developing a multi-functional material system that can serve both solar cell and thermoelectric conversion applications. The Bi1-xMxCuwOa-yQ1yTeb-zQ2z compound semiconductors exhibit dual functionality: photoelectric conversion for solar energy harvesting and thermoelectric conversion for heat-to-electricity transformation, reducing the need for separate specialized materials and simplifying overall device architecture.
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 new compound semiconductors exhibit excellent thermoelectric conversion performance, suitable for use in solar cells and thermoelectric conversion elements, with improved energy conversion efficiency and potential applications in IR windows or sensors.
Implementation Method 1
The compound semiconductor solar cell uses a compound semiconductor in a light absorption layer that absorbs solar ray to generate an electron-hole pair
Implementation Method 2
For example, for the thermoelectric conversion power generation, a temperature difference is applied to the thermoelectric conversion element to generate thermoelectromotive force
Implementation Method 3
produced by heating mixtures of Bi2O3, Bi, Cu, and Te, and optionally other elements or their oxides, at temperatures between 400 to 570°C
Data Source
AI summary
Compound semiconductors, expressed by the following formula: Bi1-xMxCuwOa-yQ1yTeb-zQ2z. Here, M is at least one element selected from the group consisting of Ba, Sr, Ca, Mg, Cs, K, Na, Cd, Hg, Sn, Pb, Eu, Sm, Mn, Ga, In, Tl, As and Sb; Q1 and Q2 are at least one element selected from the group consisting of S, Se, As and Sb; x, y, z, w, a, and b are 0≦x<1, 0<w≦1, 0.2<a<4, 0≦y<4, 0.2<b<4 and 0≦z<4. These compound semiconductors may be used for various applications such as solar cells or thermoelectric conversion elements, where they may replace compound semiconductors in common use, or be used along with compound semiconductors in common use.