Two-dimensional hybrid metal halide device controls terahertz emissions

The researchers used two-dimensional hybrid metal halides in a device that allows directional control of terahertz radiation generated by a spintronic pattern. The device has better signal efficiency than conventional terahertz generators, and is thinner, lighter and less expensive to produce.

Terahertz (THz) refers to the part of the electromagnetic spectrum (i.e. frequencies between 100 GHz and 10 THz) between microwaves and optics, and THz technologies have shown promise for applications ranging from computing and faster communications to sensitive sensing equipment. However, creating reliable THz devices has been difficult due to their size, cost, and inefficient power conversion.

“Ideally, the THz devices of the future should be light, inexpensive and robust, but this has been difficult to achieve with current materials,” says Dali Sun, assistant professor of physics at North Carolina State University and co-correspondent author of the job. “In this work, we discovered that a 2-D hybrid metal halide commonly used in solar cells and diodes, in conjunction with spintronics, can meet many of these requirements.”

The 2-D hybrid metal halide in question is a popular and commercially available synthetic hybrid semiconductor: lead iodine butyl ammonium. Spintronics involves controlling the spin of an electron, rather than just using its charge, to create energy.

Sun and his colleagues at Argonne National Laboratories, the University of North Carolina at Chapel Hill, and the University of Oakland have created a device that superimposes 2D hybrid metal halides with a ferromagnetic metal, then excites it with a laser, creating an ultra-fast spin current which in turn generated THz radiation.

The team found that not only did the 2-D hybrid metal halide device outperform the larger, heavier, and more expensive THz emitters currently in use, but also the properties of the 2-D hybrid metal halide allowed them to control. the direction of Transmission THz.

“Traditional terahertz transmitters were based on ultra-fast photocurrent,” says Sun. “But the emissions generated by spintronics produce a wider THz frequency bandwidth, and the direction of the THz emission can be controlled by changing the speed of the laser pulse and the direction of the magnetic field, which affects its turns the interaction of magnons, photons, and turns and allows us directional control. “

Sun believes this work could be a first step in exploring 2D metal halide hybrid materials as potentially useful in other spintronics applications.

“The metal halide-based 2-D hybrid device used here is smaller and more economical to produce, is robust, and performs well at higher temperatures,” Sun said. “This suggests that 2-D hybrid metal halide materials may prove superior to current conventional semiconductor materials for THz applications, which require sophisticated, more fault-sensitive deposition approaches.

“We hope that our research will launch a promising test bed for the design of a wide variety of low-dimensional metal halide hybrid materials for future solution-based spintronic and optoelectronic applications. “

The work appears in Nature Communication.