Opportunities for High Efficiency Monochromatic Photovoltaic Power Conversion at 1310 nm

We show the high efficiency and voltage possible for a monochromatic multijunction photovoltaic device operating at the telecommunication wavelength 1310 nm. We use InAlGaAs lattice matched to InP and characterize our single-junction test structure, which we show has a bandgap of 0.864 eV. We use an extended detailed balance model to predict the efficiency and voltage of a series-connected multijunction device built from the same material, and show its advantages compared to a single-junction design. We show that a series-connected 20-junction device with In
_0.532
Al
_0.097
Ga
_0.371
As can achieve a maximum power conversion efficiency over 69% in the radiative limit, at an input intensity of 5.6 × 10
⁵
W/m
²
. We also show that the device voltage at the maximum power point increases linearly with the number of junctions, with a slope larger than the single-junction voltage at maximum power point. Such behaviors of voltage and efficiency make a promising future for high-efficiency, high-voltage multijunction photonic power converters near 1310 nm.