Synthesis of nanocrystalline (CdTe:CNT) films for photo device application

Abstract

Nanocrystalline (CdTe/CNT) films were produced by the approach of the thermal evaporation at different ratio of doping and annealing temperatures. It's observed that doping with CNT films have large effect on the structure and optical characterization. The prepared samples’ structure was observed with the use of the XRD and AFM; also the optical characterization and optical constants have been discussed at different ratio of SWCNT. The X-ray diffract grams exhibit the fact that films that have been obtained are nano-crystal with cubic and hexagonal structure with a 34.15nm grain size and by increasing CNT ratio to 2wt% the crystallite size decrease to 25.9nm with cubic and hexagonal structure. The optical constants (i.e. the optical gap, coefficient of absorption, extinction coefficient, refractive index, and the dielectric constant’s real and imaginary parts) of the (CdTe/CNT)  thin films has been researched as a CNT ratio function in wave-length range of 200– 1000 nm. Analyzing the data of the optical absorption showed that the direct transitions rule is predominating. It was discovered that the coefficient of absorption, and the coefficient of extinction (k) is increased while refractive index (n) values and optical band gap decrease with the increase in CNT ratio at different annealing temperatures,