Photoresponse of a plasma-treated two-dimensional homogeneous metal/semiconductor coplanar structure

Two-dimensional platinum diselenide (PtSe₂) with thickness-dependent semiconductor-to-semimetal transition has been explored as a potential material to support further optoelectronics. The number of PtSe₂ layers can be modulated precisely by inductively coupled plasma (ICP) treatment under certain conditions. Here, an optimized ICP treatment was employed to fabricate a homogeneous metal/semiconductor coplanar structure based on PtSe₂. With the protection of the Au layer, the unetched metallic PtSe₂ works as the electrode, and the ICP-treated thinner PtSe₂ works as the channel material. The PtSe₂ photodetector with a homogeneous metal/semiconductor coplanar structure shows a photoresponse of 5×10⁴A/W.