Improving the performance of organic photodetectors by low-temperature electron beam annealing

Abstract

Organic photodetectors (OPDs) are promising candidates for next-generation optoelectronic devices due to their flexibility, low cost, and scalability. Enhancing OPD performance requires optimizing key layers such as the electron transport layer (ETL) using low-temperature processes to prevent thermal degradation. This study explores the use of low-temperature electron beam annealing (EBA) to improve the performance of Al-doped ZnO (AZO)-based ETLs. The impact of EBA irradiation time (1–8 min) on the structural, morphological, and electrical properties of AZO films was systematically analyzed. EBA effectively modulated oxygen vacancies and reduced surface roughness, lowering trap density and leakage current while enhancing charge transport. An OPD with an ETL treated by 8 min of EBA exhibited superior detectivity (2.22 × 1013 Jones at 0 V) and significantly reduced leakage current compared to a device with conventionally annealed ETLs. Importantly, the low-temperature EBA process preserved the amorphous state of AZO, making it suitable for heat-sensitive and flexible substrates. These findings demonstrate that EBA is a powerful, scalable method for ETL optimization in OPDs and offers a pathway toward high-performance, energy-efficient, and flexible optoelectronic devices.