CHESS Superlattice Layers for Wide-Temperature Thermoelectric Cooling

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Solution Overview

Problem

Conventional thermoelectric cooling structures are ineffective in varying temperature environments, limiting their performance and attractiveness, especially for high-performance electronics and sensors operating away from room temperature.

Innovation Solution

The development of controlled hierarchical engineered superlattice structures (CHESS) with varying thicknesses of Bi2Te3 and Sb2Te3 layers, formed using Metal-Organic Chemical Vapour Deposition (MOCVD) or Molecular Beam Epitaxy (MBE), which scatter phonons effectively and maintain high thermoelectric efficiency across a broad temperature range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional thermoelectric cooling structures are used, then the structure is simple and easy to manufacture, but the performance becomes limited and ineffective when temperature varies significantly from room temperature

Engineering Contradiction:

Improvethermoelectric cooling performanceVSAvoidtemperature range adaptability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The thermoelectric material is segmented into a superlattice structure consisting of multiple alternating layers of different materials (e.g., Bi2Te3 and Sb2Te3) with varying thicknesses. This segmentation creates phonon scattering interfaces that reduce thermal conductivity while maintaining electrical conductivity, enabling effective cooling performance across a broad temperature range from 100K to 400K

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different layers in the superlattice structure have locally optimized properties - alternating between materials with different thermal and electrical conductivities. The varying layer thicknesses (e.g., x, 3x, 4x, 5x, 6x, 7x multiples) create localized phonon scattering centers that adapt to different temperature conditions, allowing the structure to maintain high ZT values across varying temperatures

Inventive Principle:

Principle #3Local quality

2Reliability

If superlattice structures with varying layer thicknesses are used, then thermoelectric efficiency is maintained across broad temperature ranges, but the manufacturing complexity increases

Engineering Contradiction:

Improvethermoelectric efficiencyVSAvoidsuperlattice structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The superlattice structure employs systematic parameter variations where layer thicknesses follow geometric progressions (x, 3x, 4x, 5x, 6x, 7x times a base thickness). This parameter change strategy optimizes phonon scattering across different wavelength ranges corresponding to various temperatures, maintaining high thermoelectric efficiency while providing a scalable manufacturing approach through controlled deposition processes like MOCVD or MBE

Inventive Principle:

Principle #35Parameter changes

3Temperature

If mechanical HVAC systems are used for cooling, then cooling capability is achieved, but the system has disadvantages in weight, volume, and compactness

Engineering Contradiction:

Improvecooling capabilityVSAvoidsystem weight

Core Design Contradiction:

TemperatureVSWeight of moving object

Solution Approach 1:

The patent replaces mechanical HVAC cooling systems with solid-state thermoelectric superlattice structures that utilize the Peltier effect for cooling. This substitution eliminates moving parts, reduces system weight and volume, improves compactness, and enhances reliability while achieving comparable cooling capability across a broad temperature range through optimized phonon scattering in the superlattice structure

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

CHESS structures achieve a high thermoelectric figure of merit (ZT) greater than 2.5, enabling efficient cooling of electronics and sensors across 400K-100K temperature ranges, comparable to mechanical HVAC systems, with advantages in weight, volume, compactness, and reliability.

Implementation Method 1

controlled hierarchical engineered superlattice structures (CHESS) with varying thicknesses of Bi2Te3 and Sb2Te3 layers, formed using Metal-Organic Chemical Vapour Deposition (MOCVD) or Molecular Beam Epitaxy (MBE), which scatter phonons effectively

Methodology Applied

Scientific EffectPhonon scattering:

Implementation Method 2

Application of solid state thermoelectric cooling is expected to improve the operation of high-performance electronics

Methodology Applied

Scientific EffectSeebeck effect: Seebeck Effect

Data Source

PatentUS11908769B2Superlattice structures for thermoelectric devices

Publication Date: 2024.02.20 JOHNS HOPKINS UNIVERSITY

AI summary

Example superlattice structures and methods for thermoelectric devices are provided. An example structure may include a plurality of superlattice periods. Each superlattice period may include a first material layer disposed adjacent to a second material layer. For each superlattice period, the first material layer may be formed of a first material and the second material layer may be formed of a second material. The plurality of superlattice periods may include a first superlattice period and a second superlattice period. A thickness of a first material layer of the first superlattice period may be different than a thickness of a first material layer of the second superlattice period.