Improving electroluminescent efficiency and ultraviolet detectivity of optoelectronic integrated devices by doping a thermally activated delayed fluorescent material in an aggregation-induced emission material as an active layer

Organic integrated devices (OIDs) with ultraviolet (UV) photodetective and electroluminescent (EL) properties were fabricated using an aggregation-induced emission (AIE) featured material of 1,1,2,2-Tetraphenylethene (TPE) as host and a thermally activated delayed fluorescent (TADF) featured material of 2,4,5,6-tetrakis(carbazol-9-yl)-1,3-dicyanobenzen (4CzIPN) as dopant (doping concentration includes: 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%) in a doping system as the active layer. The 15% 4CzIPN doping OID yielded a maximum luminance of 2995 cd/m2, a relatively high detectivity of 2.8 × 1011 Jones under an illumination of 365 nm light with an intensity of 0.9 mW/cm2. The current efficiency and power efficiency of the doped device were 3.26 fold and 3.17 fold higher than those of the non-doped device, respectively. The performance improvement was analyzed by using the theory of emission quenching suppression in the AIE process, energy transfer from host to dopant, and simulation of section energy distribution variations in the active layer with the increase of doping concentration. Thus, combining AIE materials with TADF materials as an active layer is an effective way to enhance the performance of OIDs.