Electrical properties of Al2O3/WSe2 interface based on capacitance-voltage characteristics

Abstract

We report the electrical properties of Al2O3/WSe2 metal-oxide-semiconductor capacitors based on the analysis of the capacitance-voltage characteristics. Unlike previous studies, capacitance-voltage measurement in this work exhibited both high- and low-frequency behaviors. We estimated reasonable hole concentration in p-type WSe2 (∼1016 cm−3) and relatively low Al2O3/WSe2 interface trap density (∼1011 eV−1 cm−2). The low dispersion of accumulation capacitance for frequencies between 100 Hz and 1 MHz suggested low defect density in the Al2O3/WSe2 interface. These results demonstrate the feasibility of developing Al2O3/WSe2 interface with low defect density, with potentially important implications in the device fabrication of transition metal dichalcogenides.