A fast-chemically capping method in aqueous solution was developed to synthesize CdS and CdS : Ag luminescent nanoparticles and particles with sizes between 2–4 nm. The achieving of well-dispersed and narrow-sized particles in colloidal solution and also, high stability of them using mercaptoethanol (ME) as a capping agent was established. Quantum confinement effect was observed in UV-vis absorption as well as in PL spectra. PL spectroscopy also showed green emission and Ag dopants caused a faster energy transfer between CdS inter-bands. XRD patterns exhibited that both cubic and hexagonal phases exist in solutions. Ultimately, TEM images captured from QDs displayed the shapes of nanoclusters which are almost spherical.

In this work we fabricated and tested nanocrystalline schottky solar cells based on PbSe CQDs. Crystalline and monodisperse PbSe capped oleic acid CQDs were synthesized through hot injection reaction. From absorption peak and narrow photoluminescence peak of QDs in solution, CQDs size (~3 nm) and monodispersity of CQDs were determined. Photovoltaic cell structure is formed from PbSe QDs sandwiched between Al (or Ag) and ITO electrodes as electron and hole transporter layers, respectively. Current-Voltage characteristics showed carrier separation mechanism consistent with schottky device structure. The best efficient cell obtained, without any nanocrystalline film thickness optimization, with ITO\PbSe QDs\LiF\Al structure showed a PCE of 0.55%. Furthermore, oleylamine based devices with Ag as back contact exhibited the most durable cells with the life time of 21 h and survival until 5 days.