A comprehensive approach for the instability of PbTe quantum dots and design of a combinatorial passivation strategy

Hacıefendioğlu, Tuğba
Solmaz, Taha K.
Erkan, Merve
Asil Alptekin, Demet
Limited air stability circumvents the outstanding properties of the PbTe quantum dots (QDs) and hinders its utilization in the field of optoelectronics. In this respect, we present a detailed understanding on the instability of the PbTe QDs and develop a combinatorial passivation protocol based on engineering the QD surface during the growth phase and solid state ligand exchange process. The dual passivation approach yields thin films and solar cells with outstanding stabilities under ambient conditions. Prioritization of the effects of the synthetic conditions with a systematic approach discloses the crucial roles of the size, shape and stabilizing ligand/catalyst concentration on the stability. Our findings show that the stability diminishes beyond a critical size (3.6-3.9 nm) where the shape changes from octahedron to truncated octahedron. We discovered that the catalyst is a major source of the instability and optimization of its concentration leads to the smallest, extremely air stable PbTe QDs with a size less than 2 nm. We illustrate that the mid gap state formation (MGS), indispensable for any ligand exchange processes, can only be inhibited by using QDs whose capacity to withstand the severe conditions of the exchange process is improved by passivating in-situ. In-situ growth phase passivation not only control the shape by dictating the {111}/{200} facet ratio but also controls the ligand exchange rate, packing direction and MGS formation. The combinatorial passivation strategy yields air stable solar cells with a 100% increase in the efficiency and up to a fivefold increase in the short circuit current.
Solar Energy Materials and Solar Cells


Photovoltaic and photophysical properties of a novel bis-3-hexylthiophelle substituted quinoxaline derivative
GÜNEŞ, Serap; Baran, Derya; Günbaş, Emrullah Görkem; Oezyurt, Funda; Fuchsbauer, Anita; Sariciftci, Niyazi Serdar; Toppare, Levent Kamil (Elsevier BV, 2008-09-01)
We report on the photophysical properties and photovoltaic performance of a polythiophene derivative, poly-2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl)quinoxaline(PHTQ) as an electron donor in bulk heterojunction Solar Cells blended with the acceptor 1-(3-met hoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerence (PCBM). Devices were composed of PHTQ and varying amounts of PCBM (1:1, 1:2, 1:3, 1:4 w-w ratio). The components were spin cast from ortho-dichlorobenzene (ODCB) and characterized by mea...
Experimental insight into the performance characteristics of Ni-mesh semiconductor photo-electrochemical cells
Bayer, I; Eroğlu, İnci; Turker, L (Elsevier BV, 2000-04-15)
The performance characteristics of two photo-electrochemical cells with different cell configurations were investigated at 25 degrees C and within the illumination range of 70-100 W/m(2). These cells included a jacketed single cell (JSC) and a jacketed two-compartment cell (JTC). Ni-mesh was used as a counter electrode and as a backing material for semiconductor electrodes. Semiconductor electrodes were prepared by silk-screen painting technique using TiO2, WO3, PbO, Sb2S3, ZnO, Al2O3 or CuO powder mixed wi...
A new empirical many-body potential energy function application to microclusters: elements in B.C.C., F.C.C., and H.C.P. structures
Erkoç, Sevilay (Wiley, 1989-10-1)
A new empirical many‐body potential energy function (PEF) has been proposed recently, and it has been successfully applied to microclusters of various elements. Using the new PEF the microcluster calculations are extended to several elements in b.c.c., f.c.c., and h.c.p. structures.
Erkoç, Şakir (Wiley, 1989-04-01)
A new empirical many‐body potential energy function is proposed which comprises two‐ and three‐body interactions. The two‐body potential is a kind of hybrid function and the three‐body potential is expressed in terms of the two‐body interactions. The parameters of the potential energy function can be easily evaluated using dimer data and the bulk cohesive energy of the system considered. The proposed potential energy function is parameterized for several elements in f.c.c., b.c.c., and diamond structures an...
A feasibility study for controlling self-organized production of plasmonic enhancement interfaces for solar cells
Borra, Mona Zolfaghari; Gullu, Seda Kayra; Es, Fırat; Demircioğlu, Olgu; Günöven, Mete; Turan, Raşit; Bek, Alpan (Elsevier BV, 2014-11-01)
The decoration of metal nanoparticles (MNPs) by the self-organized mechanism of dewetting is utilized as a suitable method for plasmonic interface integration to large area full-scale solar cell (SC) devices. Reflection measurements are performed on both flat and textured silicon (Si) SCs in order to investigate the local plasmonic resonances of the MNPs. The effects of particle size and thickness of silicon nitride (Si3N4)anti-reflection coating layer are investigated by reflection measurements and the shi...
Citation Formats
T. Hacıefendioğlu, T. K. Solmaz, M. Erkan, and D. Asil Alptekin, “A comprehensive approach for the instability of PbTe quantum dots and design of a combinatorial passivation strategy,” Solar Energy Materials and Solar Cells, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/41647.