Luminescent Coupling as a Function of Material Quality and Current Mismatch for InGaAs Photonic Power Converters at C-band Wavelengths

Luminescent coupling in multi-junction photovoltaic devices plays an important role in mitigating the negative effects of current mismatch on the performance of the device. We incorporate luminescent coupling into a Poisson/drift-diffusion (PDD) device model and compare results to the PDD model without luminescent coupling. An increase in the spectral response of the device occurs as the number of trap states in the device is reduced, which allows more radiative coupling events to occur. Additionally, the effects of current mismatch on efficiency due to variations in thickness are mitigated due to the presence of luminescent coupling. We observe that the total thickness of the bottom subcell has a strong impact on efficiency where thinner bottom layers lead to an increase in transmission into the substrate.