Spin-coating (casting) is a commonly used technique to apply thin films on two-dimensional surfaces of wafers. The technique has important technological application in the fabrication of microcircuit and microcreators magnetic disk flat screen displays and more. Coating polymer films on a wafer is a popular way of studying the optoelectrinic properties of polymer. In addition doped polymer films are used both for scientific studies of dopants and technological applications. The experiments reported in this article can be performed by advenced undergraduate students with knowledge of spectroscopy.