Eur. Phys. J. Plus (2022) 137: 1319
https://doi.org/10.1140/epjp/s13360-022-03532-7

Regular Article

Improvement of the structural, morphological, optical, and photoelectrochemical properties of Al-doped ZnO nanorods for use in biosensors and solar cells

¹ Physics Department, Faculty of Science, Kafrelsheikh University, 33516, Kafrelsheikh, Egypt
² Physics Department, Faculty of Science, Mansoura University, Mansoura, Egypt
³ Physics Department, Faculty of Education, Humanity and Applied Sciences - Khawlan, Sana’a University, Sanaa, Yemen
⁴ Physics Department, Faculty of Science, New Mansoura University, New Mansoura, Egypt

^a hazemyahya4@gmail.com
^g elshaer@sci.kfs.edu.eg
^h mahmoud.abdelfatah@sci.kfs.edu.eg

Received: 26 July 2022
Accepted: 23 November 2022
Published online: 7 December 2022

Abstract

Pure and Al-doped ZnO (AZO) nanorods with varying concentrations (2–8%) were positively grown using a hydrothermal method. Deionized water (DI) was used to create the aqueous solutions of [Zn (NO₃)₂·6H₂O] (0.25 M), [KOH] (2.1 M), and [Al (NO₃)₃·9H₂O]. Samples have been analyzed by XRD, SEM, EDX, FTIR, UV–Vis spectrophotometer, PL spectroscopy, an I–V, and a photocurrent measurement system. The XRD pattern displayed polycrystalline nature of all samples. The average crystal size increases with the growth of Al ion-doped ZnO nanorods. According to SEM results, all produced ZnO nanorods have a hexagonal structure with a morphology-dependent on Al ion concentrations. FTIR analysis confirmed that functional groups appeared in the samples. Increased Al doping concentration has increased the band gap (Eg) of AZO nanorods. In PL spectra, two distinct emission peaks of ZnO nanorods were detected at around 399 and 582 nm, which are described to near-band edge (NBE) and broad deep-level emission (DLE), respectively. Photoelectrochemical measurements confirm the nanorods' negative conductivity, and increasing Al ion doping improves charge carrier transport as measured by current–voltage measurements. The outcomes present that AZO nanorods are gifted candidates for solar cell and biosensor applications.