AlGaAs/InGaAlP Tunnel Junctions for Multijunction Solar Cells

摘要

Optimization of GaInP (sub 2) GaAs dual and GaInP(sub 2) GaAs/Ge triple junction cells, and development of future generation monolithic multi-junction cells will involve the development of suitable high bandgap tunnel junctions. There are three criteria that a tunnel junction must meet. First, the resistance of the junction must be kept low enough so that the series resistance of the overall device is not increased. For AMO, 1 sun operation, the tunnel junction resistance should be below 5 x 10 (sub )(minus)2 (omega)-cm. Secondly, the peak current density for the tunnel junction must also be larger than the J(sub sc) of the cell so that the tunnel junction I-V curve does not have a deleterious effect on the I-V curve of the multi-transparent, i.e., there must be a minimum of optical absorption of photons that will be collected by the underlying subcells. The paper reports the investigation of four high bandgap tunnel junctions grown by metal-organic chemical vapor deposition.