M V Systems is based in United States

M V Systems is a company that received a SBIR Phase II grant for a project entitled: Fabrication of Low-bandgap Nano-crystalline SiGeC Thin Films Using the Plasma Enhanced Chemical Vapor Deposition (PECVD) Technique. Their their award is funded under the American Recovery and Reinvestment Act of 2009 project is to develop thin film tandem solar cells, comprising of nanocrystalline silicon and silicon carbon (nc-Si and nc-Si:C) absorber materials, with a conversion efficiency of ~20%. The phase I project successfully developed one of the key components, i.e. intrinsic nc-Si:C with a band gap, Eg, of ~ 1.5 eV and with good opto-electronic properties. This key material will be used initially in phase II to fabricate cells in a single junction configuration with an efficiency goal of ~10%. Previously, developed "device quality" nc-Si materials, with Eg ~1.1eV, were used to produce solar cells with efficiency ~8%. Integrating the two devices in a tandem junction configuration is forecast to yield efficiencies of ~18%. Further improvement in the tandem junction device efficiency,to ~20%, may be achieved via the use of buffer layers at the p/i or i/n interfaces and by increasing the grain size which would boost the open circuit voltage, Voc. Higher efficiency thin film tandem solar cells will be critical to achieving the low costs necessary to achieve widespread adoption of photovoltaic energy generating systems. M V Systems is a company that received a SBIR Phase I grant for a project entitled: Fabrication of low-bandgap nano-crystalline SiGeC thin films using the Plasma Enhanced Chemical Vapor Deposition (PECVD) technique. Their project will develop nanocrystalline SiGeC thin films with an optical bandgap (Eg) in the range of 1.6-1.8 eV, and enhanced absorption characteristics, leading to low-cost, high-efficiency (>20%) photovoltaic devices. Previous attempts at improving the photovoltaic efficiency have not been consistent and successful. The proposed approach uses plasma-enhanced chemical vapor deposition (PECVD) technique to deposit these films, which allows greater control of the process by being able to manipulate the plasma and electron temperatures to control the ion density in the plasma, with an independent control of the process parameters. This flexibility does not exist in the currently used techniques. With the proposed technique, stable and consistent films of SiGeC can be deposited on the desired substrate at moderate temperatures. If successfully developed, this technique could provide higher efficiency solar cells for the alternative energy market. The goal of highly stable films, high deposition efficiency and process scalability for large-scale manufacturing can only be achieved if the basic process can be proven. The broader impacts of this research will be in the low-cost photovoltaic (PV) devices for power generation market. If successfully completed, this research could lead to a strong partnership between solar cell manufacturers and equipment manufacturers, leading to a potentially lucrative photovoltaics market. Currently, electricity generated with available PV devices is 3-4 times more expensive as the conventional electricity. The selected materials (Si, Ge and C) for the thin film are abundantly available, which can significantly reduce the raw materials costs. A large body of basic knowledge of the requirements of solar electricity for the competitive market already exists, which makes the development of the process with a realistic performance target easy to achieve. The main challenge for achieving this goal lies in being able to control the deposition process to assure a stable and robust process, as the previous work has not been able to achieve consistent results. The initial target of producing a triple-junction thin-film solar cell is a worthy first product demonstration, which will prove the efficacy of the proposed technique, and attract third-party funding with little difficulty.