High Efficiency InGaAsN Solar Cells

This Phase I program addresses the need for solar cells with greater than 30% efficiency for use as power sources for satellite systems operating in air mass zero (AM0) solar radiation. SVT Associates proposes to meet this need by developing a tandem cell composed of InGaAsN (1eV), GaAs (1.4 eV) and InGaP (1.85 eV) lattice matched to GaAs substrates. A projected efficiency of 38% would be obtained from this tandem cell. The key innovation of this device is the deposition of the InGaAsN material. This will be done using an atomic nitrogen source and an unique surfactant to enhance the growth process. We will team up for this program with Prof. W. I. Wang's group at Columbia University who has extensive experience with the growth of InGaAsN for laser applications. Bulk films and PN structures will be deposited and characterize. The quantum efficiency of InGaAsN diodes will be measured and used to estimate the efficiency of the tandem cell.