Few-Layer WSe2 Schottky Junction-Based Photovoltaic Devices through Site-Selective Dual Doping

Seungpil Ko, Junhong Na, Young Sun Moon, Ute Zschieschang, Rachana Acharya, Hagen Klauk, Gyu Tae Kim, Marko Burghard, Klaus Kern

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)

Abstract

Ultrathin sheets of two-dimensional (2D) materials like transition metal dichalcogenides have attracted strong attention as components of high-performance light-harvesting devices. Here, we report the implementation of Schottky junction-based photovoltaic devices through site-selective surface doping of few-layer WSe2 in lateral contact configuration. Specifically, whereas the drain region is covered by a strong molecular p-type dopant (NDP-9) to achieve an Ohmic contact, the source region is coated with an Al2O3 layer, which causes local n-type doping and correspondingly an increase of the Schottky barrier at the contact. By scanning photocurrent microscopy using green laser light, it could be confirmed that photocurent generation is restricted to the region around the source contact. The local photoinduced charge separation is associated with a photoresponsivity of up to 20 mA W-1 and an external quantum efficiency of up to 1.3%. The demonstrated device concept should be easily transferrable to other van der Waals 2D materials.

Original languageEnglish
Pages (from-to)42912-42918
Number of pages7
JournalACS Applied Materials and Interfaces
Volume9
Issue number49
DOIs
Publication statusPublished - 2017 Dec 13

Bibliographical note

Funding Information:
The authors are grateful to the company Novaled for supplying the acceptor compound NDP-9. In addition, this research was supported by Nano·Material Technology Development Program through the National Research Foundation of Korea funded by Ministry of Science and ICT (NRF-2017M3A7B4049119) and under the framework of international cooperation program managed by the National Research Foundation of Korea (NRF-2016K2A9A2A14912825).

Publisher Copyright:
© 2017 American Chemical Society.

Keywords

  • Schottky junction
  • chemical doping
  • light harvesting
  • photovoltaic
  • tungsten diselenide

ASJC Scopus subject areas

  • General Materials Science

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