Description MSc masterproject:
Surface ligands exchange of iron pyrite NCs
Supervision: Dr Yu Bi tel: 2782670; Dr A. J. Houtepen tel: 2782157
In collaboration with Dr Tom J. Savenije
Short description of project:
Iron pyrite is the most promising potential solar cells material due to its suitable
bandgap(0.95eV), high absorption coefficient (105 cm-1), nontoxic, cheap and abundant1.
However, no efficient iron pyrite based solar cells have been reported. The highest
efficiency (2.8%) reported is based on the photoelectrochemical cell2. The limiting factor
is the high dark current which results in small open circuit voltages, less than 0.2V, that
are caused by iron pyrite phase impurities and more importantly, large surface states
density3. In this project, we aim to reduce the surface states density of iron pyrite
nanocrytals(NCs) film by surface passivation with short chain ligands. Different short
mono- and bidentate organic ligand such as short alkylthiols, acromatic thiols, and
alkyamines have all shown promise in achieving effective passivation of PbSe4, PbS5
NCs and so on in the past. They will be used in this project for the iron pyrite NCs
surface passivation to low the surface states density of iron pyrite NCs film, which is the
most important step to achieve the efficient iron pyrite based solar cells.
Activities within the framework of the project
Iron pyrite nanocrytals are synthesized according to literature6, and NCs film will be
made by dipcoating method. Short chain ligand such as 1,2-Ethanedithiol(EDT),
Ethylenediamine(EDA), Mercaptocarboxylic acids(MPA) will be used to exchange the
original long chain ligand on the iron pyrite NCs surface during the dipcoating process.
NMR, XPS and FTIR measurement will be performed on the samples to see if the surface
ligand exchanges succeed or not.
Reference:
1. Wadia, C.; Alivisatos, A. P.; Kammen, D. M., Materials Availability Expands the Opportunity for
Large-Scale Photovoltaics Deployment. Environ Sci Technol 2009, 43 (6), 2072-2077.
2. Ennaoui, A.; Fiechter, S.; Pettenkofer, C.; Alonsovante, N.; Buker, K.; Bronold, M.; Hopfner, C.;
Tributsch, H., Iron Disulfide for Solar-Energy Conversion. Sol Energ Mat Sol C 1993, 29 (4), 289-370.
3. Buker, K.; Alonsovante, N.; Tributsch, H., Photovoltaic Output Limitation of N-Fes2 (Pyrite)
Schottky Barriers - a Temperature-Dependent Characterization. J Appl Phys 1992, 72 (12), 57215728.
4. (a) Luther, J. M.; Law, M.; Beard, M. C.; Song, Q.; Reese, M. O.; Ellingson, R. J.; Nozik, A. J., Schottky
Solar Cells Based on Colloidal Nanocrystal Films. Nano Lett 2008, 8 (10), 3488-3492; (b) Talapin, D.
V.; Murray, C. B., PbSe nanocrystal solids for n- and p-channel thin film field-effect transistors. Science
2005, 310 (5745), 86-89.
5. (a) Pattantyus-Abraham, A. G.; Kramer, I. J.; Barkhouse, A. R.; Wang, X. H.; Konstantatos, G.;
Debnath, R.; Levina, L.; Raabe, I.; Nazeeruddin, M. K.; Gratzel, M.; Sargent, E. H., DepletedHeterojunction Colloidal Quantum Dot Solar Cells. Acs Nano 2010, 4 (6), 3374-3380; (b) Klem, E. J. D.;
Shukla, H.; Hinds, S.; MacNeil, D. D.; Levina, L.; Sargent, E. H., Impact of dithiol treatment and air
annealing on the conductivity, mobility, and hole density in PbS colloidal quantum dot solids. Appl
Phys Lett 2008, 92 (21).
6. Bi, Y.; Yuan, Y. B.; Exstrom, C. L.; Darveau, S. A.; Huang, J. S., Air Stable, Photosensitive, Phase Pure
Iron Pyrite Nanocrystal Thin Films for Photovoltaic Application. Nano Lett 2011, 11 (11), 4953-4957.