Thermoelectric mapping of p-n junctions and superlattices

Author

Lyeo, Ho-Ki ; Shi, Li ; Shih, C.K.

Author_Institution

Dept. of Phys., Texas Univ., Austin, TX, USA

fYear

2002

fDate

25-29 Aug. 2002

Firstpage

349

Lastpage

352

Abstract

An ultra-high-vacuum (UHV) scanning thermoelectric microscopy (SThEM) technique is developed for measuring the Seebeck coefficient profile across individual quantum well and barrier layers of thermoelectric superlattices. The method has been tested on a GaAs p-n junction. and is applied to InGaAs/InGaAsP superlattices. The measured thermoelectric voltage exhibits a sharp transition within a length scale of 2.5 nm, demonstrating the spatial resolution of the SThEM. The measured Seebeck and carrier concentration profiles can be valuable for investigating quantum confinement effects on enhancement of ZT of the quantum well. and for optimizing the growth parameters (thickness and doping) of high ZT superlattices.

Keywords

III-V semiconductors; Seebeck effect; carrier density; gallium arsenide; indium compounds; p-n junctions; scanning electron microscopy; semiconductor quantum wells; semiconductor superlattices; thermoelectricity; voltage measurement; GaAs; InGaAs-InGaAsP; InGaAs/InGaAsP; SThEM; Seebeck coefficient profile; UHV scanning thermoelectric microscopy; barrier layers; carrier concentration profile; p-n junctions; quantum confinement effects; quantum well; spatial resolution; superlattices; thermoelectric mapping; thermoelectric voltage measurement; Gallium arsenide; Indium gallium arsenide; Length measurement; Microscopy; P-n junctions; Spatial resolution; Superlattices; Testing; Thermoelectricity; Voltage measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Thermoelectrics, 2002. Proceedings ICT '02. Twenty-First International Conference on

Print_ISBN

0-7803-7683-8

Type

conf

DOI

10.1109/ICT.2002.1190337

Filename

1190337