Design of Promising Heptacoordinated Organotin (IV) Complexes-PEDOT: PSS-Based Composite for New-Generation Optoelectronic Devices Applications

Abstract

The synthesis of four mononuclear heptacoordinated organotin (IV) complexes of mixed ligands derived from tridentated Schiff bases and pyrazinecarboxylic acid is reported. This organotin (IV) complexes were prepared by using a multicomponent reaction, the reaction proceeds in moderate to good yields (64% to 82%). The complexes were characterized by UV-vis spectroscopy, IR spectroscopy, mass spectrometry, 1H, 13C, and 119Sn nuclear magnetic resonance (NMR) and elemental analysis. The spectroscopic analysis revealed that the tin atom is seven-coordinate in solution and that the carboxyl group acts as monodentate ligand. To determine the effect of the substituent on the optoelectronic properties of the organotin (IV) complexes, thin films were deposited, and the optical bandgap was obtained. A bandgap between 1.88 and 1.98 eV for the pellets and between 1.23 and 1.40 eV for the thin films was obtained. Later, different types of optoelectronic devices with architecture “contacts up / base down” were manufactured and analyzed to compare their electrical behavior. The design was intended to generate a composite based on the synthetized heptacoordinated organotin (IV) complexes embedded on the poly(3,4-ethylenedyoxithiophene)-poly(styrene sulfonate) (PEDOT:PSS). A Schottky curve at low voltages (<1.5 mV) and a current density variation of as much as ~ 3×10−5 A/cm2 at ~ 1.1 mV was observed. A generated photocurrent was of approximately 10−7 A and a photoconductivity between 4×10−9 and 7×10−9 S/cm for all the manufactured structures. The structural modifications on organotin (IV) complexes were focused on the electronic nature of the substituents and their ability to contribute to the electronic delocalization via the π system. The presence of the methyl group, a modest electron donor, or the non-substitution on the aromatic ring, has a reduced effect on the electronic properties of the molecule. However, a strong effect in the electronic properties of the material can be inferred from the presence of electron-withdrawing substituents like chlorine, able to reduce the gap energies.

Fabrication and Characterization of Hybrid Hole Transporting Layers of Organotin (IV) Semiconductors within Molybdenum Oxide/Poly(3,4-ethylenedyoxithiophene) Polystyrene Sulfonate Matrices

“…The presence of the bromide in this complex, with an electro-attracting capability greater than A and less than C, promotes intermolecular and intramolecular electronic transitions, without generating charge polarization. On the other hand, it is important to mention that the value of 3.42 eV obtained for the film with the C-complex is similar to the E opt obtained for thin films in PEDOT:PSS, with heptacoordinated organotin (IV) complexes having substituents that can be both electro-attractors and electro-donors [ 57 , 58 ], as previously studied by some authors of this work. With respect to hybrid films with a PEDOT:PSS matrix and graphene and organotin (IV)-based semiconductor complexes with electro-attracting substituents, such as chloride [ 59 ], and for the organotin Schiff bases in spun films applied in organic solar cells [ 60 ], the E opt obtained for the films with the A and B-complexes presents similar values and, in all cases, less than that of the film with the C-complex.…”

Designing, physiochemical confirmation, evaluation of biological and in-silico potential of Triorganotin(IV) complexes

“…The absence of vibrational bands associated with the carboxylic acid indicated carboxylate synthesis and coordination to the tin centre. The existence of two strong vibrational bands with distinct absorptions in the range of 1300-1320 cm -1 and 1527-1535 cm -1 , which correspond to the symmetric (vCOOs) and asymmetric (vCOOas) stretching vibrational modes of the carboxyl group, respectively, promoted the formation of the Sn-O bond [46]. The Δv = νas(OCO) − νs(OCO), provides important evidence for the Sn-carboxyl coordination mode [47].…”

Pentacoordinated Organotin(IV) Complexes as an Alternative in the Design of Highly Efficient Optoelectronic and Photovoltaic Devices: Synthesis and Photophysical Characterization

“…The electrical parameters µ and p 0 , evaluated in ordinary daylight, are shown in Table 6 . According to previous studies [ 28 ], the organotin(IV) complex in such devices has a carrier mobility of approximately 10 −2 –10 −1 cm 2 /V . s. In this work, the obtained values of µ are quite large compared to similar materials and to heptacoordinated organotin complexes in PEDOT:PSS films [ 28 , 69 ].…”

“…Organotin(IV) complexes have also been reported as sensitizers [ 25 ], PVC stabilizers [ 26 ], fungicides, catalysts, and active electroluminescent layers in organic light-emitting diodes (OLEDs) [ 27 ]. In addition, organotin(IV) complexes can be used in the manufacture of semiconductor films, in which their electrical conductivity can be increased by adding substituents to their molecular structure [ 28 , 29 , 30 ]. Charge transport is present in organotin(IV) films due to their π-conjugated structures and the presence of electronegative atoms and substituents coordinated to the tin atom [ 31 ].…”