Hybrid ZnO Flowers-Rods Nanostructure for Improved Photodetection Compared to Standalone Flowers and Rods

Abdullah M Al-Enizi,Shoyebmohamad F Shaikh,Meera Moydeen Abdulhameed,Afifa Marium,Asiya M Tamboli,Mohd Ubaidullah,Muhammad Fazal Ijaz,Satish U Ekar

doi:10.3390/coatings11121464

Abdullah M Al-Enizi, Shoyebmohamad F Shaikh + Show 6 more

Open Access

https://doi.org/10.3390/coatings11121464

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Abstract

Different Zinc Oxide (ZnO) morphologies have been used to improve photodetector efficiencies for optoelectronic applications. Herein, we present the very novel hybrid ZnO flower-rod (HZFR) morphology, to improve photodetector response and efficiency when compared to the prevalently used ZnO nanorods (NRs) and ZnO nanoflowers (NFs). The HZFR was fabricated via sol-gel microwave-assisted hydrothermal methods. HZFR achieves the benefits of both NFs, by trapping a greater amount of UV light for the generation of e-h pairs, and NRs, by effectively transporting the generated e-h pairs to the channel. The fabricated photosensors were characterized with scanning electron microscopy, X-ray diffraction, photoluminescence, and a Keithley 4200A-SCS parameter analyzer for their morphology, structural characteristics, optical performance, and electrical characteristics, respectively. The transient current response, current-voltage characteristics, and responsivity measurements were set as a benchmark of success to compare the sensor response of the three different morphologies. It was found that the novel HZFR showed the best UV sensor performance with the fastest response time (~7 s), the highest on-off ratio (52), and the best responsivity (126 A/W) when compared to the NRs and NFs. Hence, it was inferred that the HZFR morphology would be a great addition to the ZnO family for photodetector applications.

Highlights

In the contemporary science of photonics, Zinc Oxide (ZnO) is in high demand to replace silicon technology for optoelectronics [1,2,3,4]
Even though the NRs are distributed and densely populated, there is an obvious space between the adjoining NRs, where the illuminated UV light can be wasted on the substrate
A novel hybrid ZnO flower-rod (HZFR) was prepared for the first time and its UV sensor response was compared and contrasted with the traditional, and widely used, NRs and NFs

Summary

Introduction

In the contemporary science of photonics, ZnO is in high demand to replace silicon technology for optoelectronics [1,2,3,4]. ZnO is an amazing multifunctional material, which strategically lies on the border of ionic and covalent compounds and has potential applications in biomedicine, environmental monitoring, healthcare, photonics, optoelectronics, and advanced manufacturing. It is because of its room temperature, high-exciton binding energy (60 meV), and, most importantly, its large and direct bandgap of 3.37 eV, which makes it more pragmatic in optoelectronics. The possibility of fabricating multiple polymorphic shapes of ZnO, including nanowires, nanoflowers, nanoparticles, nanorods, nanowalls, nanotubes, nanotetrapods, quantum dots, and more, has made it even more relevant in the realms of optoelectronics, photonics, and nanoelectronics [5,6,7,8]

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