Ultraviolet (UV) photodetectors (PDs) based on high-quality well-aligned ZnO nanorods (NRs) were fabricated using both modified and conventional chemical bath deposition (CBD) methods. The modified chemical bath deposition (M-CBD) method was made by adding air bubbles to the growth solution during the CBD process. The viability and effectiveness of M-CBD were examined by developing UV PDs based on ZnO NRs. The ZnO nano-seed layer was coated on a glass substrate utilizing radiofrequency (RF) sputtering. The impact of the different growth-times on morphology, growth rate, crystal structure, and optical and chemical properties were investigated systematically using different characterization techniques, such as field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) analysis, UV-VIS double beam spectrometer, and energy dispersive X-ray analysis (EDX), respectively. The Al/ZnO UV PDs based on ZnO nanorods were fabricated with optimum growth conditions through the two methods of preparation. This study showed that the synthesized ZnO NRs using the M-CBD method for different growth times possess better properties than the conventional method under similar deposition conditions. Despite having the highest aspect ratio and growth rate of ZnO NRs, which were found at 4 h growth duration for both methods, the aspect ratio of ZnO NRs using the M-CBD technique was comparatively higher than the conventional CBD method. Besides, the UV PDs fabricated by the M-CBD method at 5 V bias voltage showed high sensitivity, short response time, quick recovery time, high gain, low dark current, and high photocurrent compared with the UV PD device fabricated by the conventional CBD method.
This paper reports the optical properties of zinc oxide nanofilm fabricated by using organic natural products from Salvia officinalis leaves (SOL) extract and discusses the effect of the nanocrystal (NC) structure (nanoyarn and nanomat-like structure) on nanofilm optical properties. The surface-active layer of the nanofilm of ZnO nanoparticles (ZnO NPs) was passivated with natural organic SOL leaves hydrothermally, then accumulated on zinc oxide nanorods (ZnO NRs). The nanofilms were fabricated (with and without PEO) on glass substrate (at 85 °C for 16 h) via chemical solution deposition (CSD). The samples were characterized by UV-vis, PL, FESEM, XRD, and TEM measurements. TEM micrographs confirmed the nucleation of ZnO NPs around 4 nm and the size distribution at 1.2 nm of ZnO QDs as an influence of the quantum confinement effect (QCE). The nanofilms fabricated with SOL surfactant (which works as a capping agent for ZnO NPs) represent distinct optoelectronic properties when compared to bulk ZnO. FESEM images of the nanofilms revealed nanoyarn and nanomat-like structures resembling morphologies. The XRD patterns of the samples exhibited the existence of ZnO nanocrystallites (ZnO NCs) with (100), (002), and (101) growth planes. The nanofilms fabricated represented a distinct optical property through absorption and broad emission, as the optical energy band gap reduced as the nanofilms annealed (at 120 ℃). Based on the obtained results, it was established that phytochemicals extracted from organic natural SOL leaves have a distinct influence on zoic oxide nanofilm fabrication, which may be useful for visible light spectrum trapping. The nanofilms can be used in photovoltaic solar cell applications.
This paper reports on the fabrication of zinc oxide (ZnO)/germanium nanoparticles (Ge NPs)/porous silicon (PSi) photodetector for near-infrared (NIR) detection. Ge NPs are synthesized via pulsed laser ablation in liquid (PLAL) followed by spray coating onto the porous Si substrate and subsequent deposition of a ZnO layer. Field emission scanning electron microscopy (FESEM) confirms the presence of Ge NPs, along with the formation of Ge microwires and a mesh-like Ge pattern on the porous Si surface, attributed to Ge NP supersaturation during spray coating. Ge NPs act as a source of photogenerated electrons, transferring them to the ZnO layer. Additionally, the Ge microwire network facilitates barrier-dominated conduction, further contributing to the generation and transfer of photogenerated electrons. The device achieves its best performance at a bias voltage of 6 V under illumination with 805 nm light, a light intensity of 1.44 mW cm2, and a switching frequency of 6.5 Hz and responsivity of 0.16 A W⁻1.
In this work, Sr0.3Ba0.4Pb0.3Fe12O19/(CuFe₂O₄)x (x = 2, 3, 4, and 5) as strongly exchange-coupled nanosized ferrites were fabricated using a one-pot sol⁻gel combustion method (citrate sol-gel method). The X-ray diffraction (XRD) powder patterns of the products confirmed the occurrence of pure, exchange-coupled ferrites. Frequency dependencies of the microwave characteristics (MW) were investigated using a co-axial method. The non-linear behavior of the MW with the composition transformation may be due to different degrees of Fe ion oxidation on the spinel/hexaferrite grain boundaries and strong exchange coupling during the hard and soft phases.
Flexible, highly conductive, and transparent silver nanowires (AgNWs) have emerged as vital materials for advanced applications in photovoltaics, touch screens, and optoelectronics. However, their practical deployment has been hindered by issues such as poor adhesion to diverse substrates (e.g., glass and plastic) and susceptibility to ambient oxidation. In this study, we present a novel approach to overcome these challenges through the synthesis and performance evaluation of transparent conductive electrodes (TCEs) composed of AgNWs with an adhesive SiO2 protective layer deposited on glass, paper, and plastic substrates. Using a combination of polyol synthesis, RF sputtering, and spray coating techniques, we achieved robust and stable TCEs. The SiO2 coating not only significantly improved resistance to oxidation but also enhanced adhesion, mechanical stability, and durability. SiO2/AgNWs/Glass and SiO2/AgNWs/Plastic electrodes demonstrated high transmittance values of 83.36% and 69.67% at 550 nm, along with low sheet resistance of 48.5 Ω sq-1 and 50.2 Ω sq-1, respectively. This work highlights the ability of the adhesive SiO2 layer to preserve optical and electrical properties while enhancing the substrate adherence and protection against degradation.
This paper reports the structures, morphologies, optical properties, and photoconversion efficiency (η%) of the In2S3/ZnO core-shell heterostructures nanorod arrays (IZCSHNRAs) produced via the controlled successive ionic layer absorption and reaction (SILAR) cycles. As-produced samples were characterized using XRD, FESEM, TEM, UV-Vis, PL, XPS and FTIR techniques. The proposed IZCSHNRAs revealed nearly double photocurrent density and η% values compared to the pure ZnO nanorod arrays (ZNRAs). In addition, the light absorption, crystallinity and microstructures of the specimens were appreciably improved with the increase of the SILAR cycles. The deposited nanoparticles of In2S3 (ISNPs) on the ZNRAs surface was responsible for the improvement in the heterostructures, light absorption and photogenerated electron-hole pairs separation, thus enhancing the photoconversion performance. It is established that a simple SILAR approach can be very useful to produce good quality IZCSHNRAs-based photoelectrodes required for the future development of high performance photoelectrochemical cells (PECs).