Photo-Excited MX2 Heterostructures Superior to Graphene?

Illustration of an MoS2/WS2 heterostructure with an MoS2 monolayer lying on top of a WS2 monolayer. Electrons and holes created by light are shown to separate into different layers. (Image courtesy of Feng Wang group)

An international research team led by a Berkeley Lab scientist has reported ultrafast charge transfer time of below 50 femtoseconds in photo-excited MX2 heterostructures.  This research has established that MX2 materials, which are 2D semiconductors, have excellent optical and electrical properties and are highly promising for potential optoelectronic, photonic and also photovoltaic applications.

This research has been published in Nature Nanotechnology. Feng Wang, condensed matter physicist with the Material Science Division of Berkeley Lab and the Physics Department of the University of California (UC) Berkeley, is the corresponding author of the paper.

The paper is titled “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures” and the co-authors are Jonghwan Kim, Xiaoping Hong, Yu Zhang, Su-Fei Shi, Chenhao Jin, Sefaattin Tongay, Yinghui Sun, Yanfeng Zhang and Junqiao Wu.

MX2 monolayers include a single transition metal atom layer such as tungsten or molybdenum, sandwiched between two chalcogen atom layers such as sulfur.  The van der Waals force binds the resulting heterostructure. These 2D semiconductors are very similar to graphene in terms of the hexagonal honeycomb structure they possess and excellent electrical conductance.

However, the MX2 materials have natural energy band gaps unlike graphene. They can hence be used in electronic devices and transistors as their electrical conductance can be turned on and off.

Wang stated that MX2 materials have excellent optical absorption properties and, in comparison with organic photovoltaic materials, have superior electrical transport properties and a crystalline structure.

He added that the team desires to use external electrical fields to control the charge transfer process in order to use MX2 heterostructures in photovoltaic devices.

The DOE Office of Science supported this research work with an Early Career Research Award through UC Berkeley, and also the work was supported by Chinese funding agencies through the Beijing Peking University.

This news come not long after the Lawrence Berkeley National Laboratory was used to verify the three dimensional structure of a gold nanoparticle at atomic resolution and the recording of physical mechanisms that control the evolution of facets on platinum nanocube surfaces.

Alessandro Pirolini

Written by

Alessandro Pirolini

Alessandro has a BEng (hons) in Material Science and Technology, specialising in Magnetic Materials, from the University of Birmingham. After graduating, he completed a brief spell working for an aerosol manufacturer and then pursued his love for skiing by becoming a Ski Rep in the Italian Dolomites for 5 months. Upon his return to the UK, Alessandro decided to use his knowledge of Material Science to secure a position within the Editorial Team at AZoNetwork. When not at work, Alessandro is often at Chill Factore, out on his road bike or watching Juventus win consecutive Italian league titles.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Pirolini, Alessandro. (2017, August 01). Photo-Excited MX2 Heterostructures Superior to Graphene?. AZoM. Retrieved on June 17, 2024 from https://www.azom.com/news.aspx?newsID=42267.

  • MLA

    Pirolini, Alessandro. "Photo-Excited MX2 Heterostructures Superior to Graphene?". AZoM. 17 June 2024. <https://www.azom.com/news.aspx?newsID=42267>.

  • Chicago

    Pirolini, Alessandro. "Photo-Excited MX2 Heterostructures Superior to Graphene?". AZoM. https://www.azom.com/news.aspx?newsID=42267. (accessed June 17, 2024).

  • Harvard

    Pirolini, Alessandro. 2017. Photo-Excited MX2 Heterostructures Superior to Graphene?. AZoM, viewed 17 June 2024, https://www.azom.com/news.aspx?newsID=42267.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this news story?

Leave your feedback
Your comment type
Submit

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.