SBIR Phase II: Direct Conversion of Heat to Electricity with Nanowire Antenna Arrays

This Small Business Innovation Research (SBIR) Phase II project will develop enabling nanotechnology that collects and converts infrared radiation (IR) from heated sources into DC power using nanowire antenna arrays with monolithically integrated rectifying diodes (IR-AAID). The innovation uses scaleable (square meters), self-organizing, and inexpensive electrochemical processing with low cost materials to engineer antenna/diode systems to convert light from heat sources. IR-AAID can convert heat to electricity at over 40 percent efficiency and be adapted to different emitters simply by changing the antenna geometry. The best IR thermo-photovoltaic modules typically operate at less than 5 percent efficiency, cost more than $300 per Watt, require up to 2000 degree Kelvin emitter temperatures to match available bandgaps, and require expensive materials with chemically tailored compositions, that are temperature sensitive, to match specific energy applications. In Phase I, the team demonstrated the feasibility of forming nanometer scale IR collecting antenna/diode structures over large areas, developed unique measurements to independently evaluate antenna and diode performance, demonstrated materials and diode structures that will provide the required IRAAID performance, generated DC power from light with IR-AAID devices, and demonstrated 6 percent conversion efficiency with non-optimized diodes. For Phase II, the team will develop robust processing to form inexpensive (less than $2 per Watt), IR-AAID prototypes to efficiently convert light to DC power. Commercially, since IR-AAID does not require prohibitively expensive advanced lithography or direct serial nano-patterning, this effort will produce low-cost nanowire arrays with high density over relatively large areas, for heat collection. These applications will vary from portable power packs that use low temperature heat, to the generation of electricity from high temperature nuclear and conventional heat sources where noise or other environmental concerns are an issue. The enabling IR-AAID features are ideally suited for heat recovery applications, a $100B resource that is virtually untapped at present due to the limitations and costs of existing technology.