The public discussion of the master's thesis of the student (Zainab Abdul-Karim Ahmed) Department of Physics - College of Science - University of Anbar took place on Sunday 3/19/2023 in the Jaber Bin Hayan Hall for her thesis tagged:

 

 ((Synthesis and characterization of molybdenum oxide thin films decorated with silver nanoparticles))

 

 The study aimed to prepare thin films of molybdenum oxide with nanostructures using thermal-vacuum evaporation technique, then coating these films with a layer of silver nanoparticles of varying concentration in a safe, effective and environmentally friendly manner, in order to manufacture a gas sensor for detection at different concentrations of hydrogen gas, and at different operating temperatures.  .

 The results showed X-ray diffraction variation in the intensity of the crystalline molybdenum oxide diffraction peaks when it was coated with a layer of silver oxide nanoparticles of different concentration, in addition to the variation in crystal size, which indicates the possibility of using silver oxide nanoparticles to improve the crystal structure of the nanomolybdenum oxide film with a high potential for  Crystalline size control. The deposition of the nano-silver oxide layer directly contributed to increasing the electronic transition process between the valence and conduction bands of the molybdenum oxide film, in addition to reducing the electron-gap fusion processes, as an increase in the intensity of the photoluminescence emission peaks was observed, in addition to the creep  Peaks of the emission spectrum towards higher wavelengths indicate a decrease in the energy gap values, with an increase in the concentration of silver oxide nanoparticles.

 The sensitivity properties study also showed that the molybdenum oxide films had very low sensitivity when exposed to hydrogen gas at an operating temperature in the room temperature range, while a clear improvement was observed in the allergic properties of the prepared film when it was coated with silver oxide nanoparticles and at the same operating temperature, in addition to  It was observed that the molybdenum oxide film, as it was deposited, had a weak response when exposed to different concentrations of hydrogen gas, while the sensitivity of the film itself increased under the same detection conditions for hydrogen gas when it was coated with silver oxide nanoparticles.  The MoO3 layer sensor decorated with (1.5mM) AgO at room temperature achieved the highest sensitivity (129.2%) with a response time of (14sec) and a recovery time of (7.3sec).

 

 

 After extensive discussion by the committee members with the student on the subject of her thesis, the thesis was accepted

 Congratulations to the student, the College of Science and the discussion committee