CVD nanocrystalline silicon as thermoelectric material

US9472745B2 · kind B2 · utility

Assignee

• United States of America as represented by the Secretary of the Air Force · US

Inventors

• Xiao Liu · Pasadena, US
• Thomas H. Metcalf · Washington, US
• Daniel R. Queen · Silver Spring, US
• Battogtokh Jugdersuren · Arlington, US
• Qi Wang · 安丰镇, CN
• William Nemeth · Wheat Ridge, US

Key dates

• Filing date: Feb 19, 2016
• Grant date: Oct 18, 2016
• Expiry date: Feb 19, 2036

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N10/8556

Abstract

A process for forming a doped nc-Si thin film thermoelectric material. A nc-Si thin film is slowly deposited on a substrate, either by hot-wire CVD (HWCVD) with a controlled H2:SiH4 ratio R=6-10 or by plasma-enhanced (PECVD) with a controlled R=80-100, followed by ion implantation of an n- or p-type dopant and a final annealing step to activate the implanted dopants and to remove amorphous regions. A doped nc-Si thin film thermoelectric material so formed has both a controllable grain size of from a few tens of nm to 3 nm and a controllable dopant distribution and thus can be configured to provide a thermoelectric material having predetermined desired thermal and/or electrical properties. A final annealing step is used to activate the dopants and remove any residual amorphous regions.