Molecular Foundry users and scientists have developed a new method to directly measure the band gap of MoS2, which is 30% higher than expected. The study also discovered how to tune optical and electronic properties in a 2-D material.
Significance and Impact
This is the first time the MoS2 band gap has been measured; the band gap is vital for properly connecting 2-D materials in a device. MoS2 is sensitive to both optical and electronic effects and will enable creation of ultrasensitive sensors and smaller transistors.
- The researchers measured the band gap for a monolayer of molybdenum disulfide, which has proved difficult to accurately predict theoretically, and found it to be about 30 percent higher than expected from prior experiments.
- Their technique uses photoluminescence excitation (PLE) spectroscopy to measure both the exciton and band gap signals; the new method also enables the researchers to discern the differences between optical and electronic properties of the material.
- The researchers also found that the band gap was tunable by adjusting the density of the electrons in the material.