Synthesis of copper iodide (CuI) thin films by DC magnetron sputtering and insight into its properties for photonic applications

The electrical, optical, and plasma properties of CuI thin films, prepared by DC magnetron sputtering, and its potential application as a Solar blind photodetector have been investigated. The films were deposited for 30, 60, and 90 s on glass substrates. The X-ray diffraction (XRD) studies display that the CuI thin films are poly-crystalline. The scanning electron microscopic (SEM) micrographs of the thin films reveal that the film surfaces are smooth with some small grains on the surfaces. The energy dispersive spectroscopic (EDS) studies display that iodine content decreases from 68.95 wt% to 54.04 wt% with deposition time whereas copper content increases from 31.05 wt% to 45.96 wt%. Fourier transform infrared (FTIR) spectroscopic studies show that the Cu-I and CO -C bonds are present in the films. The bandgap of films has been obtained in the span of 2.93-3.11 eV, which agrees well with the previous results. A p-CuI/n-HfO 2 solar blind UV-photodetector has been designed with parameters of CuI and the Responsivity (R) of 110 mA/W and Detectivity (D*) of 4.3 × 10 30 Jones is obtained for a wavelength of 260 nm. The properties of the CuI thin films and its PD performance parameters indicate the potentiality of the CuI films in solar blind photodetectors field. The properties of the films also indicate that the potential application in photonic devices as a carrier transport layer in the future.