Beijing Researchers Develop Heptanary Monolayer Alloy to Power Next-Generation High-Responsivity Infrared Photodetectors

Beijing scientists synthesize a 7-element alloy for infrared photodetectors, achieving record 63.74 A/W responsivity via chemical vapor deposition.

By: AXL Media

Published: Apr 30, 2026, 9:38 AM EDT

Source: Information for this report was sourced from EurekAlert!

Advancing Infrared Detection via Entropy Engineering

The pursuit of high-sensitivity infrared photodetectors has led to the emergence of a sophisticated new material class known as medium-entropy alloys. In a study published in Nano Research on March 26, 2026, a research group led by Professor Jiadong Zhou from the Beijing Institute of Technology revealed the successful synthesis of a 1T' monolayer heptanary alloy. This development marks a substantial leap in materials science, providing a new foundation for optoelectronic devices that require extreme precision and high responsivity in the infrared spectrum.

A One-Step Approach to Complex Atomic Synthesis

The technical breakthrough centers on the team's ability to combine seven distinct elements, molybdenum, tungsten, iron, cobalt, sulfur, selenium, and tellurium, into a single atomically thin layer. Using a one-step chemical vapor deposition process, the researchers formed a stable medium-entropy structure. According to Professor Zhou, this method allowed for the precise regulation of the material’s properties, significantly enhancing its conductance and thermal activation energy while optimizing the Schottky barrier formed with gold electrodes.

Record-Breaking Responsivity in the Infrared Spectrum

Experimental results indicate that the heptanary alloy vastly outperforms its predecessors in detecting light at critical wavelengths. The research team reported that their devices achieved high responsivities of 27.92 A/W at 1064 nm and 63.74 A/W at 1550 nm. These figures represent a major improvement over pristine 1T' MoTe2 and other previously documented MoTe2-based photodetectors. Such high responsivity levels are essential for long-range communication and advanced imaging systems that operate in low-light infrared environments.