(color online) (a) Pb_1−xSn_xSe cubic crystal structure can be tailored into ultrathin 2D nanostructure by 2D anisotropic growth.^[82] (b) Optical image of Pb_1−xSn_xSe nanoplates (left). Histogram of Pb_1−xSn_xSe nanoplates thickness (right). AFM image of the nanoplate (inset).^[82] (c) SEM image of the Pb_1−xSn_xSe nanoplate-based device (left). Mid-infrared photodetection of Pb_1−xSn_xSe nanoplates at 1.7–2.0 μm (right).^[83] (d) SEM image of PbS nanoplate arrays (left). The photoresponsivity and detectivity of the PbS nanoplates device as a function of laser power. The wavelength of incident laser was 800 nm (right).^[13]