Growth and Characterization of CdS Thin Films on Polymer Substrates for Photovoltaic Applications

Abstract

In this work, cadmium sulfide (CdS) films were deposited on flexible polymer substrates such as polycarbonate (PC) and polyethylene terephthalate (PET). The r.f. magnetron sputtering, which is cost-effective scalable technique, was used for the film deposition. The structural and optical properties of the films grown at different sputtering pressures were investigated. When the CdS film was deposited at lower pressure, the crystallinity and the preferred orientation toward c-axis in hexagonal phase was improved. However, the optical transmittance was reduced as the sputtering pressure was decreased. Compared with the glass substrate, CdS films grown on polymer substrates were exhibited some wore structural and optical characteristics. CdTe thin film solar cell applied to sputtered CdS as a window layer showed a maximum efficiency of 11.6%.

Inorganic Thin Film Deposition and Application on Organic Polymer Substrates

“…For example, thin aluminum films (<100 nm) deposited on PET via electron-beam evaporation were more resistive than those deposited on quartz, [79] and CdS films deposited on PC and PET were reported to exhibit lower transmittance and crystallinity compared to that deposited on glass. [80] Kotnur et al used PI foil and spin-coated PI on Si wafer to deposit Ni rich Ni-Ti co-sputtered 500 nm films at 450 C. [81] They observed different growth and structure as the films deposited on both PI possessed a columnar grains structure (Zone T of the SZM) while the film deposited on SiO2/Si had a structure similar to that of Zone 2. They suggested that the out-gassing of the polymer at such high temperature could be the reason of the different structures.…”

Photosensitive Thin Films Based on Drop Cast and Langmuir-Blodgett Hydrophilic and Hydrophobic CdS Nanoparticles

“…The values of standard Gibbs free energy of these reactions clearly point out that the formation of sulfate is preferable. The reactions are irreversible [50], so during the reduction, the evolution of hydrogen (5) or formation of OH − ions can occur (6):…”

“…Semiconductor nanoparticles or quantum dots (QDs) are known to be effective materials for photovoltaic [1][2][3][4][5][6] applications due to their unique properties, such as high extinction coefficient of light absorption, size and shape-controlled tunable bandgap energy and carrier multiplication effect and so forth. Various configurations of QD based photovoltaic cells [7] have been studied.…”