Influence of the grain boundary barrier height on the electrical properties of Gallium doped ZnO thin films

Fast Response Ultra-violet Photodetectors Based on Sol Gel Derived Ga-doped ZnO

“…It is mainly due to the formation of surplus amount of neutral atoms at grain boundaries resulting in enhanced adsorption of oxygen on photodetector surface which is responsible for higher resistance or low conductivity of GZO film and hence low I off [7,15]. On UV exposure, the release of trapped electrons from surface defects or adsorbed oxygen results in the enhanced I on and hence higher value of K is obtained.…”

“…Deep level emission peak (~ 500 nm) which corresponds to oxygen vacancies becomes more intense. The higher Ga doping distorts the film crystallinity where possibility of oxygen vacancies is envisaged [7].…”

“…Doping of higher concentration of gallium in ZnO lattice has been reported to decrease its carrier concentration resulting in an increase in the resistivity of ZnO thin film. Moreover, substitution of gallium in sol gel derived ZnO without much lattice distortion is comparatively easier than any other group III elements (Al, In) as the ionic radius of Ga 3+ (0.62 Å) is smaller than that of Zn 2+ (0.74 Å) and the covalent band length of Ga-O (1.92 Å) is slightly shorter than that of Zn-O (1.97 Å) [7]. In the present work, feasibility of realizing a fast and highly sensitive UV photodetector has been shown by exploring the photoconducting properties of Ga doped ZnO (GZO) thin film using sol gel technique with 5.5 at.…”

Island‐Like AZO/Al2O3 Bilayer Channel Structure for Thin Film Transistors

“…Furthermore, in the range 220–298 K, the filed‐effect mobility can be fitted to the expression ln( µ F . T 1/2 ) ∼ T −1 , where the exponent −1 is related to grain boundary scattering mechanism for nondegenerated thin films . As usual, there are regions of extreme disorder between the grains, which are defined as grain boundaries.…”

Structural, morphological characteristics and optical properties of Y doped ZnO thin films by sol–gel spin coating method

“…ZnO is an II-VI wide band gap semiconductor which has a band gap $ 3.37 eV at room temperature and large excitonic binding energy $60 meV. As required by its applications, its electrical conductivity and optical transmittance can be tuned by doping with various dopants such as gallium, aluminum, fluorine, indium and tin [4][5][6][7][8]. In recent years, rare earth elements have been of great interest as dopant sources for ZnO because they can reduce the native point defect densities in ZnO [9,10].…”