High Oscillator Strength Interlayer Excitons in Two-dimensional Heterostructures for Mid-infrared Photodetection

The development of infrared photodetectors is mainly limited by the choice of available materials and the intricate crystal growth process. Moreover, thermally activated carriers in traditional III–V and II–VI semiconductors enforce low operating temperatures in the infrared photodetectors. 

Here we demonstrate infrared photodetection enabled by interlayer excitons (ILEs) generated between tungsten and hafnium disulfide, WS2/HfS2. The photodetector operates at room temperature and shows an even higher performance at higher temperatures. The sensitivity of ILEs to the thickness of two-dimensional materials and the external field provides an excellent platform to realise robust tunable room temperature infrared photodetectors.

Credits to Prof Zhang Yong Wei, Dr Zhang Gang

The paper was published in Nature Nanotechnology.