Oriented p-type CuI thin film growth on n-SiC epitaxial layer for ultraviolet light detection

• High-quality CuI films on SiC single crystal were prepared through copper iodization. • Smooth CuI films grow preferentially along the (1 1 1) plane. • Lattice mismatch between CuI and SiC should be the main reason for the high-quality CuI growth. • The p-CuI/n-SiC heterojunction shows a high On-Off ratio, fast response, high responsivity and detectivity to 365 nm UV light. The absence of high-quality copper iodide (CuI) films significantly limits their application in transparent optoelectronics. This study investigated the growth of CuI films on silicon carbide (SiC) substrates and evaluates their performance in ultraviolet detection. Initially, copper (Cu) films were deposited on SiC substrates using magnetron sputtering, followed by iodization to form CuI films. The continuous and smooth CuI films grew along the (111) plane. The obtained heterojunction CuI/SiC exhibited a high On-Off ratio of 4.33 × 10 6 , a rapid response time (rise time 250 ms, fall time 172 ms), a high responsivity of 68 mA/W and a high detectivity of 1.56 × 10 11 Jones.