Figure 2.

a) EL spectra for devices A–D at the current density of ≈90 mA cm⁻². b) J–V, c) L–V, d) EQE–L–PE, and e) operating lifetime curves of devices A–D. f) Performance reproducibility of the device C. The photograph in (a) shows a working device C (with an emission area of 4 mm² operated under 90 mA cm⁻²). The inset of (b) demonstrates the device structure based on periodically inserting N layers of MoO₃ in CBP, for which N varies from 0 to 3 nm.