The invention discloses a rough black
metal film for absorbing
terahertz radiation and a preparation method of the rough black
metal film. An ultra-
thin metal film is bombarded by
plasma of a
metal active
etching agent, such as fluoro, and the surface of the metal film is rough through the physical bombardment of fluoro
plasma. Simultaneously, the fluorinion energy and the fluorinion concentration are adjusted during the
etching, the fluorinion is attached to the
rough surface of the metal film, is diffused on the surface and reacts, and the metal film with enriched fluorinion is obtained. A large number of
crystal defects of fluorinion are generated on the rough metal film surface after
etching, the metal film surface is black, the structure of the black and rough metal film surface has the
high surface-to-volume ratio and low
reflectivity, the absorption performance and the efficiency of the
terahertz radiation are effectively improved, the preparation process is simple, the Micro Electronic
Mechanical System (MEMS) and the process are compatible, and the metal film and the method can be applied to the terahertz detection and imaging filed widely.