Prm1 mz8

All organic and inorganic materials were purchased from Sigma-Aldrich and iTASCO. The devices were fabricated on a patterned ITO glass substrate with a sheet resistance of 15 $\mathrm{\Omega }$ per square. MoO₃, NPB, Bphen, Liq, and Al were deposited at a rate of 0.5, 1, 1, 0.1, and 2 Å/s, respectively. The host (Bebq₂) and guest (complexes 1 and 2) were co-deposited at various doping concentrations under a high vacuum of 2  $\times$  10⁻⁶ torr. All the devices were encapsulated within Al₂O₃ using the atomic layer deposition (ALD) process under 70℃. The current density–voltage-radiance (J–V–R) and angle-resolved EL intensity characteristics of the fabricated devices were obtained with a source-measure unit (Keithley 2400) using a calibrated photodiode (FDS 100, Thorlab) and a fiber optic spectrometer (BW_UVNb, StellarNet) held on a motorized goniometer (PRM1/MZ8, Thorlabs) in a nitrogen (N₂)-filled glove box. The EQE (η_EQE) and PE (η_PE) of the devices were estimated from the measured full angular characteristics without Lambertian simplification^{50 (link)}. The operating lifetime was monitored using a McScience Polaronix M6000 OLED Lifetime Tester.

Supplementary Figure 1 shows a schematic design of the apparatus used in this study. The UV and visible light paths were setup orthogonally, nesting the surveillance system in the latter. An off-the-shelf DLP projector (Acer XD1270D) was used with an optical lens (f = 200 mm) to focus the projection into the curing volume, in the same plane as the rotation center. The UV source was provided by a DMD projector (VISITECH-LRS-4KA, Visitech, Norway) and an aspherical lens (f = 200 mm) was installed in front of the beam outlet. The two projecting centerlines were aligned so that they intersected at the rotation axis of the curing volume. The maximal projection area was 36 × 16 mm². The surveillance was illuminated by a collimated LED light source (λ = 625 nm, M625L4-C4, Thorlabs). Printing processes (e.g., Supplementary Movies 1–3), which provided feedback to experimental trial-and-error, were recorded using a CCD camera (Grasshopper3 GS3-U3-28S5C, Point Grey Research). A cylindrical test tube 15.5 mm in diameter containing photoresin was mounted to a motorized rotation stage (PRM1/MZ8, Thorlabs) located at the intersection of the two light paths. A cuboid vat containing index-matching fluid was placed outside the test tube. The walls of the vat were perpendicular to the incident beams.