Bielefeld and IFW Dresden Control Semiconductors with Terahertz Light

Researchers at Bielefeld University and the Leibniz Institute for Solid State and Materials Research Dresden have demonstrated control of atomically thin semiconductors, such as molybdenum disulphide, using ultrashort terahertz light pulses. Published on 5 June 2025 in Nature Communications, the study details a method employing nanoscale antennas to generate vertical electric fields within the semiconductor, enabling control on timescales of less than a picosecond. This approach, developed through collaborative experimental implementation and theoretical modelling, offers an alternative to traditional electronic gating and facilitates light-driven, ultrafast optoelectronic technology. The technique allows for selective alteration of the material’s optical and electronic properties, potentially impacting data transmission, cameras, and laser systems.

Terahertz Control of Two-Dimensional Semiconductors

Researchers at Bielefeld University and the Leibniz Institute for Solid State and Materials Research Dresden have demonstrated a method for controlling atomically thin semiconductors using ultrashort terahertz light pulses, a technique detailed in a publication in Nature Communications. The approach utilises terahertz radiation, positioned between infrared and microwaves in the electromagnetic spectrum, and employs nanoscale antennas to generate vertical electric fields within semiconductors such as molybdenum disulphide (MoS2). This method provides a means of achieving a Terahertz field effect within the semiconductor material itself.

Traditional methods of applying vertical electric fields for switching transistors rely on electronic gating, which is subject to relatively slow response times. In contrast, this developed technique uses terahertz light to directly generate the control signal within the semiconductor, enabling light-driven, ultrafast optoelectronic technology. Experimental results confirm the selective alteration of both the optical and electronic properties of the material using these light pulses.

The fabrication of the necessary complex 3D2D nanoantennas was undertaken at IFW Dresden, requiring iterative design and testing to achieve the desired performance characteristics. This collaborative effort between Bielefeld University and IFW Dresden underscores the importance of interdisciplinary expertise in the advancement of nanoscale optoelectronics. The fundamental concept and theoretical modelling underpinning this Terahertz field effect were developed at Bielefeld University.

Nanoantenna Fabrication and Experimental Implementation

The experimental implementation of this technique achieved control on timescales of less than one picosecond – equivalent to one trillionth of a second. This rapid control is facilitated by directly using terahertz light to generate the control signal within the semiconductor material, representing a departure from traditional electronic gating methods. The research demonstrates the ability to selectively alter both the optical and electronic properties of the material through the application of these ultrashort light pulses.

The fabrication of the complex three-dimensional two-dimensional nanoantennas necessary to achieve this Terahertz field effect was conducted at the Leibniz Institute for Solid State and Materials Research Dresden (IFW Dresden). This process involved significant iterative design and testing to ensure the antennas met the required performance specifications. The collaborative nature of the research, combining theoretical development at Bielefeld University with antenna fabrication at IFW Dresden, highlights the importance of interdisciplinary collaboration in advancing nanoscale optoelectronics.

This development could lead to ultrafast signal control devices, electronic switches, and sensors with potential applications in data transmission, cameras, and laser systems. Potential application areas extend beyond these to encompass communication systems, computing, imaging, and quantum technologies.