Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Black phosphorus-based van der Waals heterostructures for mid-infrared light-emission applications

13.07.2020

MIR spectra have been widely used for thermal imaging, molecule characterizations, and communications. MIR light source is the key component of MIR technologies. Among them, MIR light-emitting diodes (LED) show advantages of narrow linewidth, low power consumption and portability. Since the rediscovery of thin-film BP in 2014, it has received much attention due to its unique properties, such as in-plane anisotropy, high carrier mobility, and tunable band gap, etc., making BP a promising material for applications in electronics and optoelectronics.

BP has a thickness-dependent (0.3-2 eV) bandgap, and the bandgap size can be further tuned through introducing external electric field or chemical doping. Because of these reasons, thin-film BP has been regarded as a star MIR material.


a, Schematic diagram of the BP-WSe2 heterostructure. Under the excitation of light, the electron and hole pairs in WSe2 can be efficiently transmitted to BP, thereby enhancing its MIR photoluminescence.

b, Schematic diagram of the BP-MoS2 heterojunction diode. Under a positive bias voltage between BP and MoS2, the electrons on the conduction band of MoS2 can overcome the barrier, enter into the conduction band of BP, and recombine with abundant holes in BP. Thereby electroluminescence is achieved

Credit by Xinrong Zong, Huamin Hu, Gang Ouyang, Jingwei Wang, Run Shi, Le Zhang, Qingsheng Zeng, Chao Zhu, Shouheng Chen, Chun Cheng, Bing Wang, Han Zhang, Zheng Liu, Wei Huang, Taihong Wang, Lin Wang and Xiaolong Chen

Previous research mainly focused on the luminescence properties of monolayer and few-layer BP flakes (with layer number < 5 layers). However, the latest reports indicate that thin-film BP (> 7 layers) shows remarkable photoluminescence properties in MIR region.

In this report, we proposed a novel vdW heterostructure for MIR light-emission applications, built from BP and TMDC (such as WSe2 and MoS2). According to the DFT calculation, the BP-WSe2 heterostructure forms a type-I band alignment.

Hence, the electron and hole pairs in the monolayer WSe2 can be efficiently transported into the narrow-bandgap BP, thereby enhancing the MIR photoluminescence of thin-film BP. An enhancement factor ~200% was achieved in the 5nm-thick BP-WSe2 heterostructure.

On the other hand, the BP-MoS2 heterostructure forms a type-II band alignment. A natural PN junction is formed at the interface between p-type BP and n-type MoS2. When a positive voltage bias is applied between BP and MoS2 (Vds > 0), electrons in the conduction band of MoS2 can cross the barrier and enter into the conduction band of BP.

At the same time, the majority of holes are blocked at the interface inside BP due to the large Schottky barrier of the valence band. As a result, an efficient MIR electroluminescence is achieved in the BP-MoS2 heterostructure.

The BP-TMDC vdW heterostructures show many merits, such as simple fabrication process, high efficiency, and good compatibility with silicon technology. Hence, it provides a promising platform for investigating silicon-2D hybrid optoelectronic systems.

Xiaolong Chen | EurekAlert!
Further information:
http://dx.doi.org/10.1038/s41377-020-00356-x

More articles from Physics and Astronomy:

nachricht Manifestation of quantum distance in flat band materials
05.08.2020 | Institute for Basic Science

nachricht First radio detection of an extrasolar planetary system around a main-sequence star
04.08.2020 | Max-Planck-Institut für Radioastronomie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New Strategy Against Osteoporosis

An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.

Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...

Im Focus: AI & single-cell genomics

New software predicts cell fate

Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...

Im Focus: TU Graz Researchers synthesize nanoparticles tailored for special applications

“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.

Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...

Im Focus: Tailored light inspired by nature

An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.

Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...

Im Focus: NYUAD astrophysicist investigates the possibility of life below the surface of Mars

  • A rover expected to explore below the surface of Mars in 2022 has the potential to provide more insights
  • The findings published in Scientific Reports, Springer Nature suggests the presence of traces of water on Mars, raising the question of the possibility of a life-supporting environment

Although no life has been detected on the Martian surface, a new study from astrophysicist and research scientist at the Center for Space Science at NYU Abu...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“Conference on Laser Polishing – LaP 2020”: The final touches for surfaces

23.07.2020 | Event News

Conference radar for cybersecurity

21.07.2020 | Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

 
Latest News

Manifestation of quantum distance in flat band materials

05.08.2020 | Physics and Astronomy

Discovery shows promise for treating Huntington's Disease

05.08.2020 | Health and Medicine

Rock debris protects glaciers from climate change more than previously known

05.08.2020 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>