Gallium Nitride and ArSenide Plasma Epitaxy – GASPE

The goal of the GASPE project is to achieve epitaxial growth of III-V materials at low temperature (~ 200°C) using a non-equilibrium plasma based on a physical vapour deposition approach (PVD). These III-V materials, including gallium arsenide (GaAs) and gallium nitride (GaN), have significantly higher electron mobility and complementary optical properties (direct bandgap) with silicium (indirect bandgap) and can potentially play a major role in conjunction with Si in photovoltaic and micro-electronics. For example, the combination of epitaxial-grade thin films made of GaAs and Si could pave the way of producing tandem solar cell with solar cell efficiency as high as 44 % (theory) when Si solar cell is limited to 30% efficiency. As far as microelectronic application is concerned, one can mention the strong interest of GaN, either when replacing actual Si components or, in an economic and efficiency point of view, by ‘grafting’ GaN on top of silicon components in order to outperform the device without removing the existing silicon component while seeing electrical features increase significantly.
Along with targeting materials that possess the quality to envision their use in the applications mentionned above, this project also aims at achieving a breakthrough in the understanding of the complex elementary processes that makes possible the synthesis of crystalline films at low temperature by plasma.