Samarium3+-doped CdSe quantum dots for improved electro-optical properties

Abstract

Abstract Cadmium Selenide (CdSe) quantum dots (QDs) semiconductors having direct band gap exists in different colours which depends on the size of the particles. Doping can be easy in semiconductors but adding impurities in quantum range was always considered as challenging. In the present work, we have carried out studies on the doping of CdSe QDs with Samarium 3+ (Sm3+) impurities. Four different sizes of particles were synthesised by kinetic growth route using 3-mercaptopropionic acid (3-MPA) as the capping agent. The prepared samples were characterized by ultra violet-visible (UV) and photoluminescence (PL) for their optical properties and fourier transform infrared spectroscopy (FTIR) for vibrational studies. The evidence of doping was traced by the results from the optical properties A blue shift in the absorbance spectra was recorded when compared with undoped CdSe QDs. This shift was attributed due to the transfer of energy from the host material to the dopant. The broadband PL spectra covering the entire visible range were recorded for undoped and doped QDs. In undoped CdSe QDs only band edge emission was noticeable, but after incorporating Sm3+ dopant defects were generated in QDs. Sm3+-doped CdSe QDs showed emission spectra including band edge and defect driven emissions.