Enhanced Photodetector Performance of Nanostructured MoO<sub>3-<i>x</i> </sub> Thin Films by Inert Annealing
Anibrata Mondal, Y. Ashok Kumar Reddy
Abstract
In this research work, the effect of annealing temperature on the performance of molybdenum trioxide (MoO3)-based metal–semiconductor–metal (MSM) planar-structured ultraviolet (UV) photodetector is studied. The MoO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{3}-{x}}$ </tex-math></inline-formula> thin films are grown at 5.0% of oxygen partial pressure onto the SiO2/Si substrate through the sputtering technique. Later, the as-deposited thin films are inertly annealed at 150 °C, 250 °C, and 350 °C in the ambience of inert gas (Ar). From the field emission scanning electron microscopy (FESEM) image, the prominent formation of nanorod-based morphology is observed for the sample annealed at 350 °C and it can increase the surface-area-to-volume ratio of the sample, which helps it to produce more number of charge carriers and causes to increase the photocurrent of the device. The current–voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> ) characteristics of the Ag/MoO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{3} -{x}}$ </tex-math></inline-formula> /Ag-based test devices depict the ohmic contact in the Ag-MoO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{3} -{x}}$ </tex-math></inline-formula> interface. The sample annealed at 350 °C shows a high photocurrent of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$21.21 \mu \text{A}$ </tex-math></inline-formula> , a fast response time of 60 ms, and a high responsivity of 2.905 A/W. Finally, this research work could provide a platform for the advancement of superior photodetectors in optoelectronics devices.