Title :
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
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;
Conference_Titel :
Thermoelectrics, 2002. Proceedings ICT '02. Twenty-First International Conference on
Print_ISBN :
0-7803-7683-8
DOI :
10.1109/ICT.2002.1190337
