| 摘要 |
<p>A high-efficiency 3- or 4-junction solar cell (10) is disclosed with a theoretical AMO energy conversion efficiency of about 40 %. The solar cell (10) includes p-n junctions (14, 16, 18), formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions (22, 24, 26). An optimal germanium (Ge) p-n junction (20) can be formed in the substrate (12) upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell (10). Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell (10) by metal-organic chemical vapor deposition (MOCVD).</p> |
