Структурные, оптические и термоэлектрические свойства тонких ZnO:Al пленок, полученных атомно-слоевым осаждением

Abstract

Thin films of aluminum doped zinc oxide were grown using atomic layer deposition at a temperature of 200 ° C. Using X-ray diffraction, it was found that thin ZnO: Al films have peaks from the (100), (002), (110) and (201) planes of the hexagonal ZnO phase. The (101) and (102) planes were also detected using electron diffraction. Thin ZnO: Al films grow smooth with a root-mean-square roughness of Rq of 0.33 nm and characteristic nanocrystallite sizes of ~ 70 and ~ 15 nm without additional phases associated with aluminum or aluminum oxides. The transmission at a wavelength of 550 nm, taking into account the substrate, was ~ 96%. The refractive indices and absorption coefficients of thin ZnO: Al films in the wavelength range of 250–900 nm were found. The maximum values ​​for the refractive and absorption coefficients were 2.09 at a wavelength of 335 nm and 0.39 at a wavelength of 295 nm, respectively. The optical band gap was 3.56 eV. The resistivity, the Seebeck coefficient and the power factor of thin ZnO: Al films were ~ 1.02 · 10-3 Ohm · cm, ~ - 60 μV / K and 340 μW · m-1 · K-2 at room temperature, respectively. The maximum power factor reached 620 μW · m-1 · K-2 at a temperature of 200 ° C.