Investigation on tuning of WS_2/SiC band gap with an external electric field

摘要

An optical material WS_2 thin film on SiC substrate was synthesized. Both 15nm and 150nm thickness of WS_2 films weredeposited on a n-doped SiC substrate by pulsed laser deposition (PLD) method. Tungsten disulfide films weresuperimposed face to face, and silicon carbide was used as the electrode to apply an electric field ranging from 0Vm to0.18v m. The experimental results showed that band gap were continuously tunable from 2.017ev to 1.507ev. The firstprinciple calculation by using Quantum Espresso also was performed to simulate the band gap change with the increaseof an external electric field. It is found that the band gap of WS_2/SiC film changes from 1.973ev to 1.488ev as an electricfield applied perpendicularly to the film ranging from 0Vm to 0.18v m. The consistency of experimental results andthe first principle calculation was found.