Fabrication and Characterization of High-Quality UV Photodetectors Based ZnO Nanorods Using Traditional and Modified Chemical Bath Deposition Methods

Ahmed Fattah Abdulrahman,Azeez Abdullah Barzinjy,Samir Mustafa Hamad,Naser Mahmoud Ahmed,Sabah Mohammed Ahmed,Munirah Abullah Almessiere

doi:10.3390/nano11030677

Abstract

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.

Highlights

Introduction distributed under the terms andThe ultraviolet (UV) photodetector is a very significant optical device that can be used in a wide area of applications such as biological analysis, environmental analysis, space, optical communication, military, and civilian requests [1]
There are several techniques that are used for synthesizing ZnO materials, such as chemical bath deposition (CBD) method, spray pyrolysis, hydrothermal synthesis, chemical vapor deposition, sol-gel technique, vapor phase transport, successive ionic layer adsorption reaction (SILAR), electrodeposition, and modified chemical bath deposition (M-CBD) [4]
Al/ZnO UV PDs based on ZnO NRs were fabricated with optimal growth duration for both preparation methods

Summary

Introduction

Introduction distributed under the terms andThe ultraviolet (UV) photodetector is a very significant optical device that can be used in a wide area of applications such as biological analysis, environmental analysis, space, optical communication, military, and civilian requests [1]. Nanomaterials 2021, 11, 677 exceptional characteristics, such as the direct optical energy band-gap of 3.37 eV, radiation hardness, outstanding sensitivity to absorb oxygen on the surfaces, high optical gain, high chemical stability, and temperature resistance [2] In these fields of application, rapid response (rise) and retrieval (fall) times are the key UV detection properties that facilitate faster feedback. There are several techniques that are used for synthesizing ZnO materials, such as chemical bath deposition (CBD) method, spray pyrolysis, hydrothermal synthesis, chemical vapor deposition, sol-gel technique, vapor phase transport, successive ionic layer adsorption reaction (SILAR), electrodeposition, and modified chemical bath deposition (M-CBD) [4] Among all these growth methods mentioned above, the M-CBD method is a fascinating technique that possesses high performance, and it is the most effective and efficient method for UV photodetector fabrication based on different ZnO nanostructures. It decreases the probability of standardized response and provides the oxygen throughout the CBD reaction [5]

Methods

Results

Conclusion