SBIR Phase I: Direct Optical Control of High Power Using Silicon Carbide

The broader impact/commercial potential of this project is progress towards greater security and stability for the power grid through better control and reduced energy consumption. Because of the greater speed, decreased transition time, and increased capability, greater power systems simplification and reduced costs will result. The total world market for power semiconductors is estimated to be $16 billion in 2014 rising to $28 billion by 2020. Asia dominates this market. The expected high power, high frequency, low cost device from this effort will be an attractive alternative to existing power semiconductor devices. A competitive and disruptive technology such as this device, and a growing demand for more efficient high-power switching devices in more applications will provide growth and potential for the US to gain a greater share in this market. Power equipment manufacturers will be able to develop smaller, lighter and less expensive inverters for renewable energy and simpler topologies for grid-tied storage systems and industrial motor speed control. Power supplies for medical, transportation and industrial equipment can be made more efficient, smaller and less expensive. Simpler switching configurations for power transmission and faster fault interruption to prevent widespread power failures will also be possible. This Small Business Innovation Research (SBIR) Phase I project is a feasibility study of optically driven, high power switching and control using silicon carbide. Control in the bulk of the material eliminates the semiconductor control junction that exists in standard power devices. This approach is based on extensive government laboratory research that light incident on specially doped wide bandgap materials such as SiC causes the bulk of the material to become controllably conductive. A deeper understanding of this characteristic enables a novel, highly efficient, cost effective device, capable of switching high power at much higher switching frequencies. Bulk conduction also enables greater capability than in existing semiconductor devices as power flow is not limited to the narrow space charge region at the junction. Samples of doped SiC will be selected for optimal carrier recombination characteristics and will be driven by light emitting diodes or diode lasers to demonstrate 15 kV switching at 100 kHz and eventually 10 A in an integrated four terminal package. The eventual goal is a demonstration of switching 30 kV, 20 A, at 1000 kHz, with a transition rate of >10 MV/ìs, and duty cycle greater than 50%.