A promising polarization-sensitive ultraviolet photodetector based on the two-dimensional ZrNBr-ZrNCl lateral heterojunction with enhanced photoresponse: A theoretical prediction

Highlights: • Robust photogalvanic effect in the two-dimensional lateral ZrNCl-ZrNBr heterostructure. • The photoresponse is largely enhanced by up to 3 orders of magnitude, as compared to the photodetector composed of the homogenous monolayer ZrNCl or ZrNBr. • High polarization sensitivity of the photocurrent is achieved with an extinction ratio up to 5. Photogalvanic effect (PGE) enables a self-powered and highly polarization-sensitive ultraviolet photodetection (UV-PHD), however the photocurrent generated in the PGE is usually small, leading to a lower photoresponsivity. Here, using quantum transport simulations, we propose a self-powered UV photodetector composed of the two-dimensional lateral ZrNBr-ZrNCl heterojunction. Robust PGE photocurrent is generated in a broad UV range from 3.5 to 6.5 eV at zero bias due to the noncentrosymmetry of the photodetector. The photocurrent is enhanced by up to 3 orders of magnitude, as compared to that in the monolayer ZrNBr and ZrNCl, and moreover, a good polarization sensitivity is obtained with an extinction ratio of up to 5.0. Our result propose that the PGE photocurrent can be effectively enhanced by an appropriate lateral heterojunction, and shows a promising application of the lateral ZrNBr-ZrNCl heterojunction in the self-powered and polarization-sensitive UV-PHD.