Alvarado, Samuel

Samuel Alvarado

Associate Professor of Inorganic Chemistry

Chemistry and Biotechnology
Office: 259 Centennial Science Hall
Phone: 715-425-3871

Email: samuel.alvarado@uwrf.edu

Education:

B.A. – Augustana College (IL), 2010
Ph.D. – Iowa State University, 2015

Courses Taught:

CHEM 121 - General chemistry lecture and lab
CHEM 322 and CHEM 325 - Inorganic chemistry lecture and lab

Research Interests:

Quantum dots are semiconductor particles with diameters between 1-100 nanometers. These particles are larger than small molecules, but smaller than bulk semiconductors (which can still micrometer-sized). The smallest range of quantum dot sizes includes “magic sized” nanoclusters, which have known chemical formulas such as Cd₁₃Se₁₃ and Zn₃₄S₃₄. Quantum dots act as tunable light absorbers and emitters – by changing the size of a quantum dot, it can be made to emit colors of light ranging from red to blue.

Example elemental compositions of quantum dots include CdS, CdSe, or InP. These materials can be tuned to luminesce and absorb light across the visible spectrum, which has made them useful in consumer electronics like televisions. However, some of these materials are relatively toxic or are uncommon in the Earth’s crust.

My research focuses on understanding the chemistry of magic sized quantum dots. Topics include:

• Developing luminescent materials by introducing small amounts of transition metal ions into magic sized ZnS quantum dots.
• Studying the electronic structure of transition metal-doped ZnS quantum dots by experimental methods and computational modeling.
• Investigating the chemical reactions of magic sized ZnS quantum dots in solution.

Publications:

1. Bhattacharjee, U.; Long, M.; Rosales, B. A.; Alvarado, S. R.; Vela, J.; Petrich, J. W. “Using ATTO Dyes to Probe the Photocatalytic Activity of Au-CdS Nanoparticles.” J. Phys. Chem. C, 2017, 121, 676–683.
2. Alvarado, S. R.; Shortt, I.; Fan, H.-J.; Vela, J. “Assessing Phosphine-Chalcogen Bond Energetics from Calculations.” Organometallics, 2015, 34, 4023–4031. DOI: 10.1021/acs.organomet.5b00428
3. Alvarado, S. R.; Guo, Y.; Ruberu, T. P. A.; Tavasoli, E.; Vela, J. “Inorganic Chemistry Solutions to Colloidal Semiconductor Problems.” Coord. Chem. Rev., 2014, 263, 182–196. DOI: 10.1016/j.ccr.2013.09.001
4. Humphries, M. E.; Pecak, W. E.; Hohenboken, S. A.; Alvarado, S. R.; Swenson, D. C.; Domski, G. J. “Ruthenium(II) supported by phosphine-functionalized N-heterocyclic carbene ligands as catalysts for the transfer hydrogenation of ketones.” Inorg. Chem. Commun., 2013, 37, 138–143. DOI: 10.1016/j.inoche.2013.09.046
5. Guo, Y.; Alvarado, S. R.; Barclay, J. D.; Vela, J. “Shape-Programmed Nanofabrication: Understanding the Reactivity of Dichalcogenide Precursors.” ACS Nano, 2013, 7, 3616–3626. DOI: 10.1021/nn400596e
6. Alvarado, S. R.; Guo, Y.; Ruberu, T. P. A.; Bakac, A.; Vela, J. “Photochemical vs. Thermal Synthesis of Cobalt Oxyhydroxide Nanocrystals.” J. Phys. Chem. C, 2012, 116, 10382–10389. DOI: 10.1021/jp301459s