High-Performance Self-Powered Broadband Photodetectors Based on a Bi2Se3 Topological Insulator/ReSe2 Heterojunction for Signal Transmission

Topological insulators (TIs) hold considerable promise for the advancement of optoelectronic technologies, including spectroscopy, imaging, and communication, owing to their remarkable optical and electrical characteristics. This study proposes a novel combination of Bi⁢2Se⁢3 TIs and ReSe⁢2 for self-powered broadband photodetectors with high sensitivity and fast response time. The Bi⁢2Se⁢3/ReSe⁢2 heterojunction photodetector achieves broadband response spectra ranging for 375 nm to 1 μm. It demonstrates a significant responsivity of 64 mA/W at a wavelength of 600 nm (1 mW/cm⁢2), exhibits a rapid response speed of 345 μs rise/336 μs fall time, and has a 3 dB bandwidth of 1.4 kHz under zero-bias conditions. The high performance can be attributed to the suitable energy band structure of Bi⁢2Se⁢3/ReSe⁢2 and high carrier mobility in surface states of Bi⁢2Se⁢3. Excitingly, self-powered TIs photodetectors allow for high-quality signal transmission. The TIs employed in photodetectors can stimulate the production of new optoelectronic features, but they could also be used for highly integrated photonic circuits in the future.