Experimental data of change of tetracene and halide perovskite photoluminescence with applied magnetic field, a spectrum of a bilayer and time resolved photoluminescence when exiting and measuring at different wavelengths.

Modelling results of:

i) The change in the density functional theory (DFT)-level bandgap with number of repeating tetracene units in different directions and associated inputs and outputs from DFT codes.

ii) Input and output of calculations DFT and post-DFT calculations of singlet and triplet states in bulk tetracene.

iii) The change in the DFT-level bandgap of CsPbI3 with number of repeating units, for both CsI and PbI2 terminations. Associated input and outputs from DFT calculations.

iv) Projected density of states for a tetracene molecule on the surface of a halide perovskite (with different orientations). Associated input and outputs from DFT calculations.

v) Projected density of states for tetracene/halide perovskite bilayers (with different orientations of tetracene and surface terminations of the halide perovskite). Associated input and outputs from DFT calculations.

vi) The difference in DFT and post-DFT energy levels calculated for toy models of tetracene on halide perovskite (both CsI and PbI2 surface terminations). Associated input and outputs from DFT and post-DFT calculations.