High-speed infrared two-dimensional platinum diselenide photodetectors

Abstract

Two-dimensional (2D) layered platinum diselenide (PtSe2) offers attractive optoelectronic properties including chemical stability in air, high electron mobility at room temperature, a non-zero thickness-dependent bandgap, and optical absorption that extends from visible to infrared wavelengths. We report the use of PtSe2 for high-speed photodetectors. In this work, we experimentally demonstrated that chemical-vapor-deposition-grown PtSe2 thin-film photodetectors can measure picosecond optical pulses. Finger-like electrodes are used to excite a plasmonic mode to enhance light absorption of the devices. The measured bandwidth of this device was ∼4.5 GHz. An improved bandwidth of about 17 GHz was achieved in an alternative electrode design which has smaller capacitance. The photodetector was stable, and maintained similar performance after several months' exposure to air. The PtSe2 is an attractive 2D material for high-speed optoelectronic devices and is a viable alternative to graphene and black phosphorus, potentially offering even better performance in certain applications because of its longer term stability and non-zero bandgap.