Enrichment of Charge Carrier Mobility, Quantum Efficiency and Lifetime Behavior of Emissive Polymer for Hybrid Photodetector Utilization

This research aims to enhance the optoelectronic characteristics of the MEH-PPV (Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]) emissive layer by introducing zinc oxide (ZnO-30nm) nanoparticles, to achieve specific properties. The MEH-PPV hybrid composite films were fabricated using spin coating followed by hot plate thermal annealing with varying ZnO nanoparticle concentrations of 1–7 wt%, with a 2 wt% span. The fabricated device with the structure of indium tin oxide/Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate/MEH-PPV with ZnO (0–7 wt%)/aluminum top electrode was comprehensively characterized, including PL performance, absorption behavior, charge carrier mobility, quantum efficiency, lifetime, and transient current-voltage performances. The optimal results were achieved with a 3 wt% ZnO composition, showing better charge movement with carrier mobility of 7.94 × 10−5 cm2/V·s and quantum efficiency of 36.5%. This optimized composition showed enhanced PL emission with 70% improvement, with the operational lifetime of 146 h. The absorption spectrum was also increased by 1.32 a.u. relative to pure MEH-PPV, and the photocurrent decay response was reduced to 0.86 µs and the photovoltage decay response to 1.23 µs. Thus, the paper confirmed that adding ZnO helped overcome the intrinsic limitations of MEH-PPV with a 3 wt% ZnO composite, a promising option for use in high-performing hybrid photodetectors.