Fig. 1. Tandem-like device architecture, working principle, and materials.

(A) Schematics of PD architecture. (B) Illustration of optical field distributions for visible and NIR wavelengths in the two optically active layers based on FAMAPbI₃ visible absorber and PM6:Y6 NIR absorber. For visible λ up to 650 nm, photons are predominantly absorbed by the perovskite film, while, for NIR λ (850 nm), photon absorption occurs within the organic BHJ layer and is subjected to cavity effects. (C) Schematics of the visible wavelengths filtering the tandem-like PD. HTL and ETL stand for hole and electron transport layer, respectively. The collection of photocarriers generated in the perovskite film is blocked by the perovskite/PFN-Br interface. (D) EQE as a function of wavelength (colored circle) of tandem-like devices using different perovskite/BHJ combinations, as indicated in the legend. EQE spectrum is compared with that of single PPD (black line) and single OPD (red line) and with the difference of their EQE shapes (dotted black line with colored area).