SnSe Single Crystal Sn Vacancy Band Structure Control
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Solution Overview
Problem
The existing methods for improving thermoelectric performance of SnSe materials do not effectively modify the electronic band structure without additional processing steps, limiting their efficiency in thermoelectric power generation.
Innovation Solution
Introducing Sn vacancies into single crystal SnSe by controlling the cooling rate during synthesis, which adjusts the valence band maximum energy and increases the power factor by modifying the electronic band structure, thereby enhancing thermoelectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing methods are used to improve thermoelectric performance of SnSe materials, then some performance improvement may be achieved, but additional processing steps are required and the electronic band structure modification is not effective
Solution Approach 1:
The patent applies preliminary action by controlling the cooling rate during the crystal growth process to pre-establish the desired electronic band structure and Sn vacancy concentration. This preliminary control during synthesis eliminates the need for subsequent additional processing steps to modify the band structure, thereby improving thermoelectric performance while maintaining process simplicity.
Solution Approach 2:
The patent utilizes parameter changes by systematically varying the cooling rate parameter during crystal growth to achieve optimal Sn vacancy concentration and electronic band structure. By changing this single parameter, the method effectively modifies the material's electronic properties and thermoelectric performance without requiring complex additional processing.
2Reliability
If Sn vacancies are introduced by controlling cooling rate, then electronic band structure is modified and power factor increases, but the synthesis process requires precise cooling rate control
Solution Approach 1:
The patent employs parameter changes by establishing specific cooling rate ranges (0.5-5 K/h) to control Sn vacancy formation. This systematic parameter control enables effective modification of the electronic band structure and power factor while maintaining manageable manufacturing precision requirements through defined process windows.
3Reliability
If single crystal SnSe is used to achieve low thermal conductivity, then thermoelectric performance is improved, but the electronic band structure cannot be effectively modified without additional processes
Solution Approach 1:
The patent applies preliminary action by incorporating Sn vacancy control directly into the single crystal growth process. This preliminary modification of the crystal structure during synthesis achieves both low thermal conductivity (inherent to single crystal SnSe) and effective electronic band structure modification simultaneously, eliminating the need for additional post-processing steps.
Solution Approach 2:
The patent merges two functions into a single process: growing the single crystal structure (which provides low thermal conductivity) and introducing Sn vacancies (which modify electronic band structure). By combining these functions in the crystal growth step, the method achieves improved thermoelectric performance without requiring separate additional processes.
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 introduction of Sn vacancies into single crystal SnSe increases the power factor and electrical conductivity, leading to improved thermoelectric performance and efficiency in thermoelectric power generation.
Implementation Method 1
heating a mixture including Sn2+ and Se2−
Implementation Method 2
cooling the mixture at a cooling rate greater than 0 and equal to or less than 3 K/h
Data Source
AI summary
Provided is a method of preparing an SnSe thermoelectric material including (a) heating a mixture including Sn2+ and Se2−, (b) cooling the mixture at a cooling rate greater than 0 and equal to or less than 3 K/h, and forming single crystal Sn1-xSe (where 0<x<1), and an SnSe thermoelectric material prepared thereby and including Sn vacancies.