Abstracts Book - IMRC 2018

• SA2-O014 Invited Talk
UTILIZATION OF PHOTOLUMINESCENT DOWN-CONVERTING
QUANTUM DOTS IN PHOTOVOLTAIC STRUCTURES AND
CHARACTERIZATION OF THE ANOMALOUS RED-SHIFT EXHIBITED
BY COLLOIDAL QUANTUM DOT SOLUTIONS
Arturo A. Ayón 1 , Gregory Guisbiers 2
1
University of Texas at San Antonio, Physics and Astronomy, United States. 2 University of
Arkansas, Physics and Astronomy Department, United States.
We discuss the synergistic effects of nanotexturization and down-shifting
quantum dots on the power conversion efficiency of solar cells. The identified
best practices conducive to increasing the efficiency of said devices employing
photoluminescent quantum dots are discussed herein. Additionally, an
anomalous Stokes shift effect has been observed in solutions containing a
collection of down-shifting Carbon quantum dots (CQDs) of different sizes that
is anticipated to have a positive influence on the power conversion efficiency of
solar cells. Specifically, with an excitation wavelength of 390 nm, CQDs whose
diameter was determined by the applied current during synthesis, exhibited
emission peaks centered around 420 nm. However, the solution comprising the
mixture of the previously synthesized CQDs of different diameters, was
observed to be red-shifted to 515 nm. Furthermore, the aforementioned redshifting
effect was also observed in CdTe QDs when added to the CQDs mixedsolution
(CMS). Thus, whereas a mixture of CdTe QDs of different sizes, exhibited
a down-shifted photoluminescence centered around 555 nm, the peak was
further red-shifted to 580 nm when combined with the CMS. Quantum dot
characterization included crystal structure analysis as well as photon absorption
and photoluminescence wavelengths. Nano-Thermodynamics has been
employed to understand the underlying Physics of the observed effect. Future
research endeavors to control and exploit the aforementioned anomalous
effect are also discussed.
Acknowledgment:
NSF, ARO and AFOSR
Keywords: Quantum Dots, Nanoalloys, Nanotechnology
Presenting authors email: Aayon@utsa.edu