Eka Nurfani, Cindy Chotimah, Wahyu Solafide Sipahutar, Resti Marlina
The effect of pH in hydrothermal synthesis on the structural properties and photodetector performance of ZnO nanorods has been successfully investigated. Calculating the molar ratio among zinc acetate dihydrate (ZAD), methenamine (ME), and sodium hydroxide (NaOH) is important to obtain pH variations. By applying ZAD:ME (1:1), ZAD:NaOH (1:1), and ZAD:ME:NaOH (1:1:1), pH variations of 5.96 (S1), 6.80 (S2), and 7.23 (S3) were obtained, respectively. Morphological images from field-emission scanning electron microscope (FESEM) show that the average diameter of ZnO nanorods is about 75.6 nm (S1), 146.4 nm (S2), dan 173.8 nm (S3). From the optical properties analysis carried out using UV–visible spectroscopy (UV–vis), the transmittance increased by increasing the pH, while the absorption showed a different pattern. The bandgap values are 2.6, 3.1, and 3.2 eV for the S1, S2, and S3 samples, respectively. Furthermore, based on current–voltage (I-V) curves, the S3 sample has the highest UV sensitivity with a very fast response time (7.1 s for rise time and 3.9 s for decay time). This study is important to realize future optoelectronic technology. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.
Department of Materials Engineering, Institut Teknologi Sumatera (ITERA), South Lampung, 35365, Indonesia; Center for Green and Sustainable Materials, Institut Teknologi Sumatera (ITERA), South Lampung, 35365, Indonesia; Research Center for Biomass and Bioproducts, National Research and Innovation Agency (BRIN), Cibinong, 16911, Indonesia