13.2% efficiency double-hetero structure single-junction InGaAsN solar cells grown by MOVPE

Low background carbon concentration InGaAsN (E_g ∼ 1.18 eV), lattice-matched on a GaAs substrate, was grown at high temperatures (∼600 °C) using metalorganic vapor phase epitaxy. This material was used as an alternative to GaAs as the middle cell in triple-junction InGaP/GaAs/Ge solar cells. The low background carbon concentration (∼5 × 10¹⁶cm^-3) and increased depletion region width of the InGaAsN material significantly improves the solar cell performance over that found with dilute-nitride cells grown at lower growth temperatures (∼525 °C). The device performance of the solar cells with the low carbon InGaAsN active region yielded a short-circuit current density, open-circuit voltage, fill factor, and efficiency values of 26.05 mA/cm², 0.67 V, 75.85%, and 13.2%, with antireflecting coating, respectively.