Improving photodetector performance of PANI nanofiber by adding rare-earth La2O3 nanoparticles

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2023-02, Vol.129 (2), Article 135
• Main Authors: Hassen, Maryam M., Ibrahim, Isam M., Abdullah, Omed Gh, Suhail, Mahdi H.
• Format: Article
• Language: English
• Subjects: Applied physics; Characterization and Evaluation of Materials; Charge transfer; Chemical synthesis; Condensed Matter Physics; Glass substrates; Lanthanum oxides; Machines; Manufacturing; Materials science; Nanocomposites; Nanofibers; Nanoparticles; Nanotechnology; Optical and Electronic Materials; Photometers; Physics; Physics and Astronomy; Polyanilines; Processes; Rare earth elements; Silicon substrates; Spin coating; Surfaces and Interfaces; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-023-06415-5

Nanocomposites based on Polyaniline (PANI) nanofibers (NFs) and Lanthanum oxide (La 2 O 3 ) nanoparticles (NPs) were successfully synthesized using hydrothermal and chemical methods, respectively. Thin films of pure PANI and PANI/La 2 O 3 nanocomposites have been deposited by spin-coating technique on both n-Si and glass substrates. The prepared thin films have been tested using XRD, FE-SEM, and UV–Vis and were examined as photodetectors. The XRD pattern showed the crystalline nature of PANI NFs’ film and the cubic structure of PANI/La 2 O 3 films. FE-SEM images of pure PANI proved that the film prepared has a nanofiber-like structure, whereas the PANI/La 2 O 3 nanocomposite films proved that La 2 O 3 NPs capped with PANI NFs. The UV–Vis spectrum of pure PANI showed the absorption peaks of B and Q bands at 340 and 651 nm, while for PANI/La 2 O 3 films, the position of the two bands shifted to 320 and 620 nm revealing a charge transfer between the PANI NFs and La 2 O 3 NPs. The optical band gap value of PANI/La 2 O 3 hybrid nanocomposite films decreases from 2.97 to 2.81 eV for B-band and from 1.49 to 1.43 eV for Q-band upon increasing the La 2 O 3 content from 1 to 4 vol.% in the PANI NFs. On the other hand, incorporating La 2 O 3 into PANI showed remarkably improved photodetector performance of the system. The maximum sensitivity values of the photoconductive detectors were observed for PANI/La 2 O 3 nanocomposites deposited on an n-Si substrate which were approximately 342.72 and 5069.69% at 660 and 965 nm, respectively.