Posted in | News | Semiconductor | Electronics

Creating a 2D Transistor from Inorganic Molybdenum Disulfide

The field of semiconductor research is constantly exploring materials with enhanced properties for use in semiconductors. Writing in Nature, Andras Kis has recounted how his team created a two-dimensional semiconductor based on a single layer of inorganic molybdenum disulfide.

Study: How we made the 2D transistor. Image Credit: Intothelight Photography/

Constructing Semiconductors out of Ever-Thinner Materials

Moore’s law dictates that the number of transistors on a semiconductor will double every two years. In pursuit of this, the materials used in semiconductors keep getting thinner and are heading toward the atomic limit. How thin a material can be is a key question in semiconductor design. Solving this conundrum will inform the future of the industry, providing innovative technologies that help the industry take a huge step forward, solving the limitations of semiconductor design.

One answer seemed to be using graphene. This material is comprised of a single layer of carbon atoms., but suffers significantly from a lack of bandgap, which is crucial for semiconductor materials. To improve this and make graphene more suitable for this application, techniques such as applying a vertical electric field or shaping it into nanoribbons have been explored, but these techniques present technical challenges.

A Different Approach

Because of these challenges, the team led by Andras Kis decided to take a different approach. They decided to start with a two-dimensional material that already has a bandgap, rather than trying to induce one in the material.

Taking inspiration from his days as a PhD student, Kis explored inorganic molybdenum disulfide as an alternative material. At the time, researchers were investigating carbon nanotubes, but a smaller group was working on exploring the properties of molybdenum disulfide and tungsten diselenide nanotubes. Thus, the basis of studying 2D molybdenum disulfide and related two-dimensional materials was formed.

His group at EPFL in Switzerland began to explore making a 2D molybdenum disulfide transistor. The thin films were exfoliated from bulk crystals. The microscopy supplies market sells molybdenite, which is a mineral comprised of molybdenum disulfide with a similar appearance to graphite. Thus, the transistor material was easy to source from commercial suppliers.

Building the Device

Building the transistor initially proved challenging using this material. One early challenge was finding a suitable contact material. By the end of 2009, progress was made on solving this difficulty, when transistors using five-to-six-layer thick molybdenum disulfide were routinely produced. These early transistors displayed current modulation of six orders of magnitude. However, single-layer transistors were still facing issues with noise and resistance.

2D Materials Beyond Graphene

Video Credit: Quantum Light University of Sheffield/

This was overcome by using a system using atomic layer deposition to deposit insulating materials layer-by-layer, which was developed by Aleksandra Radenovic. To further explore protection against air and moisture and shield the 2D material from impurities, the team investigated the application of hafnium oxide. This worked better than the research team expected.

The first generation of the team’s monolayer transistor device showed enhanced electrical properties and performance. Current and resistance showed significant improvement, and on/off current ratios over 1 x 108 were observed. Furthermore, leakage currents to the order of hundreds of femtoamperes lower were achieved.

The results of the study were published in 2011 in the journal Nature Nanotechnology. The research demonstrated the possibility of constructing transistors out of 2D materials other than graphene that displayed superior electrical properties.

Parallel Research

Around the same time as this groundbreaking research, groups at the University of California, Berkeley, Trinity College Dublin, and Columbia University were investigating molybdenum disulfide for its properties and fabrication methods. Results of the research carried out by these teams provided several significant advances in the field.

Firstly, the groups at Berkeley and Columbia presented research that showed monolayered molybdenum sulfide exhibits photoluminescence due to its bandgap. The team at Trinity College Dublin developed a liquid-phase exfoliation process to mass-produce molybdenum disulfide as well as other 2D monolayer materials. The results of these research studies alongside the manufacture of 2D monolayered molybdenum disulfide transistors paved the way for the expansion of the field.

The Future

Two dimensional transistors are revolutionary for the semiconductor industry. These atomically thin devices have the potential for continued scalability of transistors in a multitude of devices. However, many studies on 2D transistors have thus far been limited to proof-of-concept, with much work needed in the field to assess these devices and realize their commercial viability in the electronics industry.

As the need for atomic scale materials becomes more intense, research into thinner and thinner devices is gathering pace. The groundbreaking research by Kis and his team provided new opportunities for physicists, chemists, and engineers working in the semiconductor industry to realize the true limits of semiconductor technologies.

Further Reading

Kis, A (2021) How we made the 2D transistor [online] Available at:

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Reginald Davey

Written by

Reginald Davey

Reg Davey is a freelance copywriter and editor based in Nottingham in the United Kingdom. Writing for AZoNetwork represents the coming together of various interests and fields he has been interested and involved in over the years, including Microbiology, Biomedical Sciences, and Environmental Science.


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

  • APA

    Davey, Reginald. (2021, November 17). Creating a 2D Transistor from Inorganic Molybdenum Disulfide. AZoM. Retrieved on May 27, 2024 from

  • MLA

    Davey, Reginald. "Creating a 2D Transistor from Inorganic Molybdenum Disulfide". AZoM. 27 May 2024. <>.

  • Chicago

    Davey, Reginald. "Creating a 2D Transistor from Inorganic Molybdenum Disulfide". AZoM. (accessed May 27, 2024).

  • Harvard

    Davey, Reginald. 2021. Creating a 2D Transistor from Inorganic Molybdenum Disulfide. AZoM, viewed 27 May 2024,

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

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.