This project will result in a photovoltaic (PV) topping cell designed for >25% efficient operation at temperatures above 400C within two years. In year 3, the project will demonstrate the integration potential of the topping cell into a concentrating solar power module. The proposed PC topping cell, shown in the figure below, has the following advantages: Low cost as already demonstrated by the cost of LEDs and power electronic InGaN devices with similar technology. Rapid scalability based on the large, existing commercial InGaN market for the same technology sectors. High reliability due to the thermal stability of nitride based materials with refractory metal contacts in contrast to conventional III--V materials which are unstable at > 400 C. Efficient thermal contact between the topping cell and the thermal system through conformal mounting directly on the solar thermal absorber. Once feasibility has been demonstrated, we believe the proposed topping cell has low risk and rapid applicability. This is achieved because all the key innovations have been proven in other commercial application areas: 1) the thermal stability of InGaN materials is well known, 2) the ability to control device--dependent thermal effects is investigated and shown in high power electronics and light emitters, and 3) the use of thermionic emission for escape from quantum wells (QWs) is amply demonstrated in solar. Preliminary calculations at 100x concentration show that the proposed technology solution achieves ARPA--Es goals for the FOCUS Category 1B program (i.e., > 25% PV efficiency at >400 C operation with > 55% hybrid system efficiency) using a technology that has already demonstrated robust lifetime and performance in solid state lighting applications.
|Effective start/end date||6/4/14 → 8/29/17|
- DOE: Advanced Research Projects Agency-Energy (ARPA-E): $3,899,998.00