ELFT HÍRADÓ

[Tamas Gal <gal AT fizika.ttk.pte.hu>]

A PTE Fizikai Intézete és a PAB Fizikai és Csillagászati Szakbizottsága
szeretettel meghívja





*Chikán Viktor*



(University of California,
Szegedi Tudományegyetem/ELI)







*Doping colloidal quantum dots *



*c. előadására*








Helyszín: PTE-TTK, A/401. terem

Időpont: 2014. szep. 25., csüt. 14.00





*Minden érdeklődőt szeretettel várunk!*


*Part one: Doping Colloidal Quantum Dots*


 Semiconductor quantum dots exhibit fascinating and important physical and
chemical properties that can hold the potential to play crucial role in
transforming the photovoltaic industry, creating new business opportunities
and producing electricity to address the increasing global energy needs.
Producing relatively efficient solar cells from quantum dots has been
already demonstrated by many research groups. An important goal is to
better equip these quantum dots for photovoltaic cells by controlling their
electrical properties via chemical doping. The challenge of doping process
is to control the chemical synthesis of these quantum dots to increase
uniformity of the resulting doped quantum dots. In the discussion, gallium,
tin and indium doping of CdSe quantum dots will be used as examples to
highlight these challenges as well as demonstrate possible solutions for
the challenges. The majority of the currently available materials to
produce the needed quantum dots do not hold the potential at industrial
scale due to limited supplies, and environmental concerns. Our group’s
effort focuses on the recently discovered semiconducting and ‘green’ iron
silicide nanoparticles. Although these particles are successfully
synthesized, their potential is not fully realized yet.



*Part Two: Pulsed magnetic field induced fast drug release from magneto
liposomes via ultrasound generation *


 Fast drug delivery is very important to utilize drug molecules that are
short lived under physiological conditions. Techniques that can release
model molecules under physiological conditions could play an important role
to discover the pharmacokinetics of short lived substances in the body.
Here an experimental method is developed for the fast release of the
liposomes’ payload without a significant increase in (local) temperatures.
This goal is achieved by using short magnetic pulses to disrupt the lipid
bilayer of liposomes loaded with magnetic nanoparticles. The drug release
has been tested by two independent assays. The first assay relies on the AC
impedance measurements of MgSO4 released from the magnetic liposomes. The
second standard permeability assay is based on the increase of the
fluorescence signal from 5(6)-Carboxyfluorescein dye when it the dye is
released from the magneto liposomes. The efficiency of drug release ranges
from a few percent to up to 40% in case of the MgSO4. The experiments also
indicate that the magnetic nanoparticle generate ultrasound via
magnetostriction, which is thought to have a role in the release of the
model drugs from the magneto liposomes.