feb-13-2015

Mitk’El B. Santiago Berríos, Ph.D.

Assistant Professor, Researcher I

Universidad Metropolitana

Effect of the ligand in PbSe and ZnO particles: synthesis, characterization, electrochemical characterization for solar energy harvesting applications

Semiconductor materials have attracted interest due to their potential as active elements in the development of harvesting-energy conversion technologies.  Lead selenide(PbSe) and zinc oxide(ZnO) materials have been proposed as active materials for in the systematic construction of different solar cells.¹Lead selenide, for example, have been proposed due to their exceptional strong quantum confinement effect.  However, due to the synthesis of these materials long chained hydrocarbons are used to control the size and shape of these materials.  Nevertheless, these materials are air sensitive, which affects the efficiency of a solar cell device.  Therefore, the need to use ligands that protects the semiconductor core has been an effort recently to increase robustness in the construction of solar cell technologies.  Recently, Rodriguez et al. have devise a method to use wet chemistry to synthetize PbSe with benzoic acid.²These materials demonstrated to be more resistant to air oxidation and to aqueous solution.  In the other hand, ZnO a wide gap semiconductor have been proposed for the construction of solar cells due to their high electron mobility and ease of the construction for a transparent electrode.  In our group, we are studying the effect of the ligand in terms of the crystal structure, electronic spectra and electrochemical behavior.  These materials have demonstrated to form from rods to thin films, which allow to us to devise strategies for the construction of solar cells.  This seminar will focus on the recent advances made in the Nanoscience Laboratory at Universidad Metropolitana.

1.         Choi, J. J.; Lim, Y.-F.; Santiago-Berrios, M. E. B.; Oh, M.; Hyun, B.-R.; Sun, L.; Bartnik, A. C.; Goedhart, A.; Malliaras, G. G.; Abruña, H. D.; Wise, F. W.; Hanrath, T., PbSe Nanocrystal Excitonic Solar Cells. Nano Letters 2009,9 (11), 3749-3755.

2.         Rodríguez-Rodríguez, W. A.; Colón, J.; Guzmán, R.; Rivera, H.; Santiago-Berríos, M. E. B., Synthesis, characterization and electrochemical characterization of lead selenide sub-micron particles capped with a benzoate ligand and prepared at different temperatures. Materials Research Express 2014,1 (3), 035906.