Ultrabroadband Photoconductive Topological Material with Exceptional Multienvironmental Stability.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• Topological crystalline insulators (TCIs) show promise for optoelectronics due to broad absorption, fast response, and stability.
• Previous research lacked scalable synthesis methods for TCIs.

Purpose of the Study:

• To develop a scalable synthesis for a two-dimensional (2D) SnSe0.9Te0.1 TCI.
• To demonstrate its application in robust broadband photodetection from visible to long-wave infrared (LWIR).

Main Methods:

• One-step upscaled synthesis of 6-inch 2D SnSe0.9Te0.1 TCI.
• Fabrication of a photodetector based on the synthesized material.
• Systematic evaluation of photodetection performance and environmental stability.

Main Results:

• Achieved photoresponsivity up to 11.17 A W⁻¹ and detectivity up to 1.07 × 10¹² Jones at 1064 nm.
• Demonstrated photodetection from visible (532 nm) to LWIR (4000 nm) wavelengths.
• Confirmed material stability under prolonged air exposure, thermal stress, humidity, and water immersion.
• Observed photoresponse to subtle thermal radiation from human fingers.

Conclusions:

• The one-step upscaled synthesis enables robust broadband photodetection.
• The topological electronic structure, achieved by Te substitution in SnSe, facilitates phase transitions for enhanced photodetection.
• The SnSe0.9Te0.1 TCI is a promising material for stable and sensitive optoelectronic applications.