Effects of aluminum doping in CdS thin films prepared by CBD and the performance on Schottky diodes TCO/CdS:Al/C

Aluminum dopant effect upon cadmium sulfide (CdS) films was analyzed as well as its impact of the resultant properties in the functional device, ITO/CdS:Al/C. The optical and electrical properties of the CdS films were affected due to the aluminum doping, and as a result, the Schottky diode performance shows dependency on the Al doping concentration. The Al-doped CdS films and devices were characterized electrically and optically. The results show that as the dopant concentration increases, the film resistivity its reduced from 108 to 107 Ω cm, the work function decreases from 4.7 to 4.3 eV and the energy bandgap slightly increases from 2.45 to 2.48 eV. Regarding the devices, the on/off ratio ∼106, and the ideality factor shows an improvement from 3 to 1.5. The diode presents a final leakage current around ∼10−3 A. The doping effect on CdS films results in the improvement of the overall performance of the device. We can conclude that this treatment can be used in optoelectronic devices such as solar cells or photodiodes.