Page 29 - Annual Report_21-22

Direct laser writing of conducting diamond on flexibles

Objectives: power of more than 75% leads to the burning of the Teflon
sheets. So, it is crucial for us to control the environment
• Synthesis of conducting diamond on polyimide and
polystyrene substrates using a CO2-laser based direct during laser writing on the Teflon. More characterization
laser writing method in CH4, N2/trimethyl boron gas studies will be required to analyze the obtained DNPs,
atmospheres at room temperature. which are under progress.
• Several characterization tools will be used to investigate
the properties of as-grown diamond materials.
• The laser engraver machine purchase order was installed
on 08/23/2021.

• Initially, we have synthesized diamond nanoparticles
(DNPs) on Teflon sheets by varying the laser power from
30-80%. However, Raman spectra from the particles
obtained from Teflon sheets (Fig. 8) do not show the
formation of DNPs.
Bypassing CH gas, we further optimized the conditions
4
to synthesis DNPs with higher laser power. The powder
collected during laser writing was subjected to Raman
analysis. From the comparison of the Raman data of the
powder with the flow of with CH4 and without CH4, we
found that the formation of the DNPs takes place when Fig.8: Raman spectra of carbon materials fabricated on
synthesized using CH4 gas (Fig. 9). However, the 75% laser Teflon sheets using laser engraver machine at various
power is the maximum laser power we can go through, The laser powers, aiming to achieve diamond nanoparticles.

Fig. 9: Raman spectra of DNPs fabricated on Teflon sheets using laser engraver machine using CH4 gas.

Further, the growth conditions will be optimized in terms writing for the formation of the DNPs, we will develop a
of (i) distance between laser to the substrate, (ii) laser model based on ZnSe optical windows, using acrylic as the
focus, (iii) input gases, etc. to achieve good quality DNPs. base materials for transparency during the laser writing
Also, to avoid the atmospheric condition during the laser (Fig. 10). The work is under progress.

ANNUAL REPORT 2021-22 27