Work

Generalization of the two-diode IV model for background-doped thermophotonic LEDs

Year: 2026

Type: article

Abstract: In recent work, shifted-junction LEDs were developed that yield extremely low non-radiative losses. However, their IV curves show features that standard two-diode modelscannot explain. In this work, these features are described using a generalization of thetwo-diode model that employs a non-radiative current starting at an ideality factor $n_{id} = 1$,that saturates to $n_{id} = 2$ behavior beyond a threshold voltage. This saturating diode (SD)model works particularly well for IV curves that show neither a clear $n_{id} = 1$ or $n_{id} = 2$regime. The SD model is verified using drift-diffusion simulations and measured IV curvesof shifted-junction LEDs. Subsequently, this framework is applied to establish the radiativecurrent and coupling efficiency required to reach wall-plug efficiencies surpassing unity, whichis required for electroluminescent cooling. Specifically, it is demonstrated that the deviceparameters required to reach the cooling regime have all been achieved in separate devices,assuming the radiative current changes in line with what is expected at high light extractionefficiencies from previous numerical studies.

Source: Solar Energy Materials and Solar Cells

DOI: 10.1016/j.solmat.2026.114398