Hydrothermally Synthesized Cadmium Selenide Quantum Dot for Solar Cell Application

Abstract

Hydrothermal synthesis autoclave reactor offers simple, safer and environmentally friendlier process for the preparation of valuable nanoparticles. In this study, cadmium selenide (CdSe) quantum dot (QD) were successfully synthesized via one-step hydrothermal synthetic route at 195 oC. The reactant mixtures used for the synthesis was added into Teflon and comprises 15 mg of selenium (Se) powder, 15 mg of cadmium oxide (CdO), 20 ml of octadecene (OTD), 10 ml of oleic acid (OA) and 1 ml of trioctylphosphine (TOP). The synthesis lasted for 3 hours 20 minutes. The synthesized CdSe QDs were characterized using optical absorption spectroscopy, fluorescence spectroscopy (PL), scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The broad absorption peak of the sample depicted the suitability of the sample for photovoltaic application while the fluorescence peaks was assigned to band edge emission to shallow and deep trap states. AFM and SEM microstructure images revealed the surface morphology and the crystal orientation of CdSe QD while the QD size and particles distribution were obtained using TEM and FESEM. The EDX were used to obtain the compositional ratio of the materials in the synthesized CdSe QD sample. The formation mechanisms were discussed on the basis of the experimental results and the quantum dots were found to be stable for about three months.