Large and Tunable Photothermoelectric Effect in Single-Layer MoS2

• Published in: Nano letters Vol. 13; no. 2; pp. 358 - 363
• Main Authors: Buscema, Michele, Barkelid, Maria, Zwiller, Val, van der Zant, Herre S. J, Steele, Gary A, Castellanos-Gomez, Andres
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13-02-2013
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Electronics; Exact sciences and technology; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Thermal properties of condensed matter; Thermal properties of small particles, nanocrystals, nanotubes; Transistors; scanning photocurrent microscopy; Seebeck coefficient; photoresponse; photothermoelectric effect; Molybdenum disulfide nanosheets; External field; Semiconductor materials; Molybdenum sulfide; Electron hole pair; Seebeck effect; Chip; Thermal properties; Field effect transistor; Energetic efficiency; Electric field effect; Photoconductivity; Photoelectric current; Interface; Schottky barrier
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl303321g

We study the photoresponse of single-layer MoS2 field-effect transistors by scanning photocurrent microscopy. We find that, unlike in many other semiconductors, the photocurrent generation in single-layer MoS2 is dominated by the photothermoelectric effect and not by the separation of photoexcited electron–hole pairs across the Schottky barriers at the MoS2/electrode interfaces. We observe a large value for the Seebeck coefficient for single-layer MoS2 that by an external electric field can be tuned between −4 × 102 and −1 × 105 μV K–1. This large and tunable Seebeck coefficient of the single-layer MoS2 paves the way to new applications of this material such as on-chip thermopower generation and waste thermal energy harvesting.