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▲ [12a-PA2-23] Impact of LASER on Graphene Growth on Silicon using Microwave Plasma CVD
Keywords:Graphene, Plasma CVD, Graphene Schottky Solar cell
Researchers have succeeded in direct graphene growth on various insulating substrates including semiconducting silicon using microwave plasma chemical vapor deposition1. Plasma, undoubtedly plays an important role in graphene formation on insulating substrates, but its turbulent ions in hot plasma region might impair the surface beneath graphene before its nucleation and growth. This study reports, how impact of plasma ions can be reduced especially on semiconducting silicon substrate for better quality graphene on silicon for extracting higher charge transport through graphene/Si Schottky junction.
Silicon substrate was kept in a cold plasma region (with a comparatively less ion density). Cold plasma generally lacks required activation energy for graphene nucleation and growth. However, using blue laser beam illuminated on silicon substrate during growth in a cold plasma region (figure. 1A) helps in formation of graphene as shown in Raman spectrum in figure 1B. Advantage of this technique is, it prevents silicon substrate from turbulent plasma ions, hence reducing surface defects. Graphene formed in cold plasma with laser has a lowered series resistance as compared to one in hot plasma when a Graphene/Si Schottky solar cell is fabricated. Graphene is further doped with carbon dots. Carbon dots doping shows an improvement in charge transfer, enhancing higher sheet carrier current density in Ag/CarbonDots-Graphene/n-Si/n+/Al solar cell.
Silicon substrate was kept in a cold plasma region (with a comparatively less ion density). Cold plasma generally lacks required activation energy for graphene nucleation and growth. However, using blue laser beam illuminated on silicon substrate during growth in a cold plasma region (figure. 1A) helps in formation of graphene as shown in Raman spectrum in figure 1B. Advantage of this technique is, it prevents silicon substrate from turbulent plasma ions, hence reducing surface defects. Graphene formed in cold plasma with laser has a lowered series resistance as compared to one in hot plasma when a Graphene/Si Schottky solar cell is fabricated. Graphene is further doped with carbon dots. Carbon dots doping shows an improvement in charge transfer, enhancing higher sheet carrier current density in Ag/CarbonDots-Graphene/n-Si/n+/Al solar cell.