Investigating the effect of (mCP: CuPc) host–guest layer on the production of near‐infrared organic light-emitting diodes

In this study, we introduced a low-cost and effective device structure utilizing copper phthalocyanine (CuPc) as a dopant into N, N′-dicarbazolyl-3,5-benzene (mCP) for near-infrared (NIR) organic light-emitting diodes (OLEDs). Initially, an optimized reference OLED was manufactured. Then, the electroluminescent performance of the device was compared to the simulation results obtained by the Crosslight APSYS software (Advanced Physical Model of Semiconductor Devices). After confirming the simulation results, we investigated the emission spectra and external quantum efficiency (EQE) for OLEDs doped with various CuPc concentrations using the APSYS program. As a result of the transitions from CuPc's low-lying triplet state (T1) to its ground state (S0), electroluminescence was observed at about 1.1 µm. An optimized NIR OLED was fabricated with 4 wt% CuPc and demonstrated superior performance to other structures via the efficient energy transfer from the host excited states to the NIR phosphors, realizing a maximum EQE value of 0.27 % and radiance of 656 μW/cm2.