Electronic Property of PdSe₂ Thin Films Fabricated by Post-selenization of Pd Films

At present, the approaches to fabricate PdSe 2 thin films mainly focus on mechanical exfoliation and chemical vapor deposition. In this study, we report a simple and efficient method to fabricate PdSe 2 thin films on SiO 2 /Si substrates. Firstly, a Pd metal layer was deposited on a SiO 2 /Si substrate using magnetron sputtering. Then the PdSe 2 thin film was obtained through selenization of the Pd layer at certain temperatures in a vacuum quartz ampule containing Se powder. According to the cross-sectional high-resolution transmission electron microscopy (HRTEM) image, the as-grown PdSe 2 thin film has an average thickness of about 30 nm. The correlation between selenization temperature and electronic transport properties of PdSe 2 thin films was investigated. PdSe 2 thin films with a hole carrier concentration of ~10 18 cm -3 and a mobility of ~48.5 cm 2 V -1 s -1 are realized at a low selenization temperature of 300 . It is worth noting that the mobility obtained by the vacuum selenization is superior to that of the p-type PdSe 2 thin films fabricated by mechanical exfoliation from bulk PdSe 2 single crystals. In addition, a relatively large room-temperature magnetoresistance (MR) of 12% is achieved for the PdSe 2 thin films selenized at 300 . With the increase in the selenization temperature from 300 , mobility and magnetoresistance decrease due to the evaporation of Se element at high temperatures. This work demonstrates that present one-step selenization process is a facile and efficient approach to synthesize PdSe 2 films, which could actually be used to prepare PdSe 2 films in a large scale and may have potential applications for next-generation electronic and magneto-electronic devices.