4.7 Article

Asymmetric photoelectric effect: Auger-assisted hot hole photocurrents in transition metal dichalcogenides

Journal

NANOPHOTONICS
Volume 10, Issue 1, Pages 105-113

Publisher

WALTER DE GRUYTER GMBH
DOI: 10.1515/nanoph-2020-0397

Keywords

Auger excitation; 2D materials; optoelectronics; transition metal dichalcogenides

Funding

  1. NSF
  2. CUA
  3. Fannie and John Hertz Fellowship
  4. Paul and Daisy Soros Fellowships for New Americans
  5. US Office of Naval Research
  6. Laboratory-University Collaboration Initiative (LUCI) program of the DoD Basic Research Office
  7. U.S. Air Force Research Laboratory Supercomputing Resource Centers [NRLDC04123333]
  8. Elemental Strategy Initiative by the MEXT, Japan [JPMXP0112101001]
  9. JSPS KAKENHI [JP20H00354]
  10. CREST, JST [JPMJCR15F3]
  11. Vannevar Bush Faculty Fellowship Program
  12. DO
  13. NanoX/NEXT travel grant

Ask authors/readers for more resources

Transition metal dichalcogenide (TMD) semiconductor heterostructures are being actively explored as a new platform for quantum optoelectronic systems. The use of insulating hexagonal boron nitride (hBN) in state-of-the-art devices is crucial for proper device operation and interface cleanliness. Through experimental investigation, large through-hBN photocurrents generated by optical excitation in hBN encapsulated MoSe2 and WSe2 monolayer devices have been observed, providing important implications for the design of optoelectronic devices based on encapsulated TMD devices.
Transition metal dichalcogenide (TMD) semiconductor heterostructures are actively explored as a new platform for quantum optoelectronic systems. Most state of the art devices make use of insulating hexagonal boron nitride (hBN) that acts as a wide-bandgap dielectric encapsulating layer that also provides an atomically smooth and clean interface that is paramount for proper device operation. We report the observation of large, through-hBN photocurrents that are generated upon optical excitation of hBN encapsulated MoSe2 and WSe2 monolayer devices. We attribute these effects to Auger recombination in the TMDs, in combination with an asymmetric band offset between the TMD and the hBN. We present experimental investigation of these effects and compare our observations with detailed, ab-initio modeling. Our observations have important implications for the design of optoelectronic devices based on encapsulated TMD devices. In systems where precise charge-state control is desired, the out-of-plane current path presents both a challenge and an opportunity for optical doping control. Since the current directly depends on Auger recombination, it can act as a local, direct probe of both the efficiency of the Auger process as well as its dependence on the local density of states in integrated devices.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available