A highly polarization sensitive antimonene photodetector with a broadband photoresponse and strong anisotropy
Photodetectors based on two-dimensional materials have shown impressive performance including fast and broadband photoresponse and high responsivity. However, their polarization sensitivity remains to be improved. Here, we propose an antimonene photodetector having a strong polarization sensitivity with a broadband photoresponse, based on quantum transport calculations. A robust photocurrent is generated for almost the whole visible range under small bias, and it saturates at a small bias voltage for most of the photon energies. The photocurrent shows a perfect cosine dependence on the polarization angle, which originates from a second-order response to the electric field of the light. This leads to a strong polarization sensitivity to the linearly polarized light with a large extinction ratio. For a higher photon energy around 3.2 eV, a rather high extinction ratio greater than 100 can be achieved along with a larger photocurrent. Moreover, there is an evident anisotropy between the armchair and zigzag directions, as the photocurrent intensity in the zigzag direction can be approximately 17 times larger than that in the armchair direction at a small bias. These results suggest that antimonene is a promising candidate for anisotropic photodetection in the visible range especially for high frequency visible light.