Effect of lanthanum doping on the structure and optical properties of nanocrystalline vanadium pentoxide films prepared by sol–gel method

Abstract The structural and optical properties of lanthanum oxide doped nanocrystalline vanadium pentoxide films with the chemical composition xLa 2 O 3 -(1-x)V 5 .nH (where x = 0.25, 0.50 1.0 mol%) prepared by sol–gel method were studied. XRD analysis also revealed that (002) line is noticeable in pure film gets sharper addition Lanthanum, which indicates a layer intercalation between layers. average crystallite size decreased increasing Lanthanum content from 4.45 nm to 3.57 nm. By using double-beam UV–VIS spectrophotometers, studied measuring absorption, reflectance transmittance films. Some parameters like absorption coefficient α, dispersion energy parameters, refractive index n, band gap E op for various transition mechanisms, real parts imaginary part dielectric constants effective mass calculated. slightly increases La content, can be attributed lattice distortion as result indicated XRD. mechanism was found indirect allowed type relative content. assuming hydrogen model, carrier’s contents N deduced. spectrum behavior visible UV region suggests promising solution solar cells optical-electronic applications.