Research Paper — Impact of Luminescent Coupling on Perovskite–Silicon Tandem EQE

paperSetfosPaios
Written By Fluxim AG

Summary

Simulated and measured EQE showing how luminescent coupling dominates at high irradiance while shunt currents appear at low intensity.

In this work, the effects of luminescent coupling (LC) on the external quantum efficiency (EQE) of perovskite-silicon tandem(PST) solar cells are quantified by means of monochromatic transient photocurrent measurements and comprehensive optoelec-tronic simulations that take into account both optical and electrical coupling of the subcells. It is shown that, at short wavelengths,a similar response results from both LC and silicon bottom-cell shunts. The two contributions can be discriminated and quantifiedbased on bias voltage and light intensity-dependent measurements. Such measurements were conducted on state-of-the-art PSTcells and agree well with the behavior predicted by the simulations. For the case of polychromatic EQE simulations, a quenchingof the LC effects with decreasing concentration of mobile ions is found, which is explained in terms of ion-modulated recombi-nation via bulk defects.

Publication details

Zeder S. J., Krucker T., Moia D., Jenatsch S., Artuk K., Wolff C., Ballif C., Ruhstaller B., Aeberhard U. Solar RRL (2025).
DOI: https://doi.org/10.1002/solr.202500823

Fluxim tools used

Paios — Performed monochromatic EQE via transient photocurrent at varying irradiance and voltage, enabling separation of LC and shunt signatures.
Setfos — Simulated full opto-electronic behavior, including photon recycling, LC, and mobile-ion effects, validating measurements and revealing LC quenching mechanisms.

Why it matters

  • Provides a robust method to separate LC from shunt artifacts in tandem EQE.

  • Demonstrates how ion physics influences radiative and nonradiative recombination.

  • Strengthens understanding of optical–electronic coupling in next-generation tandem devices.

FAQs

How does luminescent coupling (LC) affect EQE?
LC increases bottom-cell EQE at short wavelengths by reabsorbing photons emitted by the perovskite top cell.

How did Paios measurements help separate LC from shunts?
The bias and irradiance dependence of TPC-based EQE reveals distinct voltage signatures for shunts vs LC.

Why does LC decrease when mobile ions are reduced?
Lower ion density suppresses trap saturation, increasing SRH recombination and reducing radiative re-emission

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