Structural, morphology and optical properties of CZO thin films deposited by sol–gel spin coating for optoelectronic applications

Structural, Topography, and Optical Properties of Ba‐Doped Mn3O4 Thin Films for Ammonia Gas Sensing Application

“…The peak position shifts toward high (2 θ ) angle this shift may be caused by the nonuniform strain developed due to the influence of different ionic radii Mn 2+ ( r = 0.93 ) and Ba 2+ ( r = 1.38 ), whereas the interplanar spacing shifts to lower values due to the increase in lattice parameters as Ba concentration increases. The lattice parameters, unit cell volume and bond length are calculated using VESTA software and are summarized in Table , the values are in good agreement with the work reported in literature, the crystallite size is calculated using Debye–Scherrer formula, where D , λ , and β are the crystallite size, the wavelength of the X‐ray (0.154056 nm) and the full width half maximum; respectively, it is clearly seen that the crystallite size varies with Ba concentration in Mn 3 O 4 lattice (see Table ).…”

“…The peak position shifts toward high (2θ) angle this shift may be caused by the nonuniform strain developed due to the influence of different ionic radii Mn 2þ (r ¼ 0.93 A 0 ) and Ba 2þ (r ¼ 1.38 A 0 ), whereas the interplanar spacing shifts to lower values due to the increase in lattice parameters as Ba concentration increases. The lattice parameters, unit cell volume and bond length are calculated using VESTA software and are summarized in Table 1, the values are in good agreement with the work reported in literature, [21][22][23][24][25][26][27] the crystallite size is calculated using Debye-Scherrer formula, [28]…”

“…The band gap of the sprayed films is calculated using Tauc's relation using the following equation: where α , B , and Eg are the absorption coefficient, proportionality constant, and optical band gap; respectively, the absorption coefficient is calculated by the following equation: where A and t are the absorbance and thickness, respectively, Figure shows the band gap of pure and Ba‐doped Mn 3 O 4 thin films, the values fairly agree with the work reported in literature . It is found that band gap varies as Ba concentration increases reaching a minimum value 2.85 eV in Mn 3 O 4 :Ba1% thin films, the reduction in band gap may be due to the increase in RMS roughness and crystallite size as reported earlier, it is also observed band gap decreases with the increase in unit cell volume as well as bond lengths of (Mn 2+ O) and (Mn 3+ O) in tetrahedral and octahedral sites; respectively (see Table ) as Ba concentration increases, this behavior agrees with the findings reported in literature …”

“…where A and t are the absorbance and thickness, respectively, Figure 6 shows the band gap of pure and Ba-doped Mn 3 O 4 thin films, the values fairly agree with the work reported in literature. [9,11,25,36] It is found that band gap varies as Ba concentration increases reaching a minimum value 2.85 eV in Mn 3 O 4 :Ba1% thin films, the reduction in band gap may be due to the increase in RMS roughness and crystallite size as reported earlier, [28,37] it is also observed band gap decreases with the increase in unit cell volume as well as bond lengths of (Mn 2þ ─O) and (Mn 3þ ─O) in tetrahedral and octahedral sites; respectively (see Table 1) as Ba concentration increases, this behavior agrees with the findings reported in literature. [38][39][40][41][42][43][44]…”

“…Morphological and topographic properties of the sprayed films have been studied using atomic force microscope (AFM-AA3000) and scanning electron microscope (Tescan, VEGA 3SB SEM), Figure 2 shows AFM micrographs of pure and Badoped Mn 3 O 4 thin films, it is clearly seen the films are free of cracks with nanometric grains and RMS roughness varies with Ba concentration reaching maximum value (15.9 nm) in Mn 3 O 4 : Ba1% thin films due to the increment in grain size, this behavior agrees with the previously reported findings. [28,30] Figure 3 shows SEM micrographs of the sprayed films; it can be observed the morphology changes with Ba concentration, the surface of Mn 3 O 4 :Ba1% thin films shows porous morphology, such kind of morphology provides a high surface area which is appropriate for gas sensing applications.…”