Highly efficient UV-sensing properties of Sb-doped ZnO nanorod arrays synthesized by a facile, single-step hydrothermal reaction

Abstract

The synthesis of electrical and optical property-modulated, low-dimensional metal oxide semiconductors has been adopted for the development of nanodevices. However, conventional modulation methods, such as doping and alloying, generally require rather complex processes, such as multi-step high-temperature reactions, gas-phase growth, high-vacuum processes, etc. Alternatively, in the current study, the facile and cost-effective synthesis of Sb-doped ZnO nanorod arrays (NRAs) is achieved using a simple hydrothermal growth process at 95 C. Through a single-step reaction, Sb atoms are substitutionally doped at the Zn atom sites with control of the Sb concentration. Sb dopants and Sb-induced oxygen vacancies increase the electron concentration in the ZnO NRAs, enhancing the electrical conductivity of the ZnO NRAs and inducing the further adsorption of ambient oxygen molecules on the nanorod surface. Upon UV irradiation of the highly oxygen-adsorbed, Sb-doped ZnO NRAs, the desorption of oxygen induces greater conductivity changes compared to the undoped samples. Based on this enhanced resistivity change, UV sensor devices were fabricated, and an improved reversible UV sensing performance was observed, with a $9-fold enhancement in the photocurrent of the ZnO NRAs after Sb doping. Moreover, UV sensing is achieved even under an extremely low bias of 10-6 V, suggesting the promising application of this material in extremely low-power UV sensor devices.

Tuning Optoelectronic Properties Through In‐Plane Arrangement and Point Defects in ZnO Nanorods as Prepared by Room‐Temperature DC‐Unbalanced Magnetron Sputtering

“…V O defect generates free electrons in the system that bound to adsorbed oxygen molecule generating an electronic depletion layer. Thus, ZnO nanorods surface absorb more oxygen molecule in the air due to more free electrons generated by V O leading to enhancement of electronic depletion layer . This enhancement plays an important role in scattering/trapping centers for conduction electrons that suppress the amount of dark current .…”

“…Under illumination of light, the electron–hole pairs are generated in the system, this hole recombines with the electron bound to oxygen molecules, which leads to the oxygen desorption process on the surface of the nanorods. This process induces to the decrease of electronic depletion layer and the conductivity will increase . From the schematic diagram, it can be clearly seen that for the case of ZnO nanorods MSM photodetector the amount of nanorods which contributes to the absorption and desorption process of oxygen molecule is much higher than that of p‐n heterojunction.…”

Structural, Morphological, Optical, and Electrical Properties of Sol–Gel Derived Sb‐Doped ZnO Thin Films Annealed Under Different Atmospheres

“…Many endeavored research works have been recently conducted for achieving ZnO with p‐type conductivity by doping ZnO with group I and versus elements such as Li, Na, K, N, P, As, and antimony (Sb). [ 8–14 ] Sb is among potential candidates to achieve p‐type ZnO because of a relatively heavy element compared with zinc and oxygen and good acceptor behavior. [ 15 ] It has been reported that p‐type conductivity in Sb‐doped ZnO can be achieved by Sb substitution at Zn site resulting chemical bonding with two zinc vacancies (Sb Zn –2V Zn ), then forming acceptor complex in ZnO.…”

Synthesis and characterization of Y-doped ZnO thin films prepared by spin-coating technique

“…ZnO exhibits wide bandgap of 3.37 eV, large exciton binding energy of 60 meV at ambient temperature, excellent transparency, low production cost, non-toxicity, and good stability (Sang et al, 2018;Zhang et al, 2016;Samavati et al, 2017;Li et al, 2015;Shaban et al, 2018;Stehr et al, 2015). The main applications of zinc oxide include solar cells, light-emitting diodes, laser diodes, piezoelectric devices, photosensors, thin-film transistors, auto-heaters, paints, antibacterial agents, biosensors, gas sensors, and photocatalysts (Mudusu et al, 2016;Park et al, 2015;Akhtarianfar et al, 2017;Gupta et al, 2016;Yu et al, 2016 ;Wu et al, 2016;Rajendran et al, 2016;Kim et al, 2017;Wang et al, 2015).…”