InGaP/GaAs dual‐junction solar cells with AlInGaP passivation layer grown by hydride vapor phase epitaxy

Abstract

AbstractHydride vapor phase epitaxy (HVPE), which enables low‐cost crystal growth, has garnered attention as an alternative III–V device fabrication technology to metal organic chemical vapor deposition. However, improvement in solar cell performance, through the introduction of Al‐containing materials grown by HVPE, has not been reported because of the complexity of their growth. This paper presents the solar cell applications of AlInGaP grown via HVPE using aluminum trichloride (AlCl3) as a precursor. Increasing the partial pressure of AlCl3 increased the Al composition in the AlInGaP layers. Although high concentrations of Si and O impurities were detected within the HVPE‐grown AlInGaP layers, the crystals were found to be of a quality that could be used in III–V solar cells. By using AlInGaP as a passivation layer in InGaP single‐junction solar cells, the current density was improved because of a reduction in the surface recombination loss. A conversion efficiency of 15.4% was achieved for the InGaP single‐junction solar cells measured under airmass 1.5 global solar spectrum illumination. Moreover, we developed 26.9% efficient InGaP/GaAs dual‐junction solar cells, the highest conversion efficiency in reported cells grown via HVPE. This result demonstrates an improvement in the performance of HVPE cells by introducing Al‐containing materials.