Presentation Title

High Vacuum Growth of Molybdenum-Disulfide (MoS2)

Start Date

November 2016

End Date

November 2016

Location

HUB 302-#125

Type of Presentation

Poster

Abstract

We are particularly interested in producing molybdenum-disulfide (MoS2), specifically for its transistor properties in a single (atom) layer film. This would enable the creation of smaller more flexible transistors, which in turn would greatly reduce the size of electronic devices and increase the applications of such devices. MoS2 is a transition metal dichalcogenide (TMD), and we are trying to exploit the high band gap it possesses in a mono-layer film. This is achieved by producing substrates in high vacuum with different parameters. The growth of a mono-layer sample by chemical vapor deposition (CVD) in high vacuum is dependent on many variables like the temperature of the sample and filaments, the pressure, and the distance the sample is from the heat source. High vacuum increases the potential for a purer sample. Our approach is to heat up a Si/SiO2 wafer to 600 degrees Celsius while molybdenum wires directly above the substrate are heated to 2000 degrees Celsius. Once this has been achieved we introduce carbon disulfide into the system and it reacts with the hot molybdenum wire forming MoS2, which condenses onto the substrate. We characterize our samples by looking at the Raman shift, which would contain peaks that are unique to MoS2 in cm-1 (wavenumbers). We additionally test the photoluminescence of the sample and look for a PL of around 2000 eV. 2000eV is extremely indicative of a mono-layer sample. We regularly find samples with MoS2 growth, however, a sample suggesting mono-layer, 1000-2000 PL, is much rarer.

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Nov 12th, 4:00 PM Nov 12th, 5:00 PM

High Vacuum Growth of Molybdenum-Disulfide (MoS2)

HUB 302-#125

We are particularly interested in producing molybdenum-disulfide (MoS2), specifically for its transistor properties in a single (atom) layer film. This would enable the creation of smaller more flexible transistors, which in turn would greatly reduce the size of electronic devices and increase the applications of such devices. MoS2 is a transition metal dichalcogenide (TMD), and we are trying to exploit the high band gap it possesses in a mono-layer film. This is achieved by producing substrates in high vacuum with different parameters. The growth of a mono-layer sample by chemical vapor deposition (CVD) in high vacuum is dependent on many variables like the temperature of the sample and filaments, the pressure, and the distance the sample is from the heat source. High vacuum increases the potential for a purer sample. Our approach is to heat up a Si/SiO2 wafer to 600 degrees Celsius while molybdenum wires directly above the substrate are heated to 2000 degrees Celsius. Once this has been achieved we introduce carbon disulfide into the system and it reacts with the hot molybdenum wire forming MoS2, which condenses onto the substrate. We characterize our samples by looking at the Raman shift, which would contain peaks that are unique to MoS2 in cm-1 (wavenumbers). We additionally test the photoluminescence of the sample and look for a PL of around 2000 eV. 2000eV is extremely indicative of a mono-layer sample. We regularly find samples with MoS2 growth, however, a sample suggesting mono-layer, 1000-2000 PL, is much rarer.