Resumen de Growth of doped PbS:Co^(2+) nanocrystals by Chemical Bath

O. Portillo Moreno, R. Gutiérrez Pérez, M. Chávez Portillo, M.N. Márquez Specia, G. Hernández Téllez, M. Lazcano, A. Moreno Rodríguez, R. Palomino Merino, E. Rubio Rosas

• Nanocrystalline PbS films grown by chemical bath at T = 40 ± 2 ºC onto glass slides were modified by in situ Co^(2+) -doping and their structural and optical properties were examined. By FT-IR spectra, a sharp stretching mode can be seen at ∼1384 cm^(−1) due to the vibration mode of CO^(2)_(3) ions. XRD patterns shown the growth on the zinc blende crystalline face. The grain size was determined by using X-rays diffractograms and was found at ∼28 nm and ∼13 − 25 nm for undoped and doped samples, respectively. Optical absorption spectra was used for calculating the energy band gap, and displayed a shift in the ∼1.21 − 2.21 eV range, associated with quantum confinement effect. Raman peaks at ∼210, 271, and 451 cm^(−1) , corresponding to a 1LO phonon mode, a two-phonon process, and a 2LO phonon mode respectively were also recorded. The surface and grain size of the films were measured by AFM studies.