The effect of aromatic ring size in electron deficient semiconducting polymers for n-type organic thermoelectrics

Abstract

N-type semiconducting polymers have been recently utilized in thermoelectric devices, however they have typically exhibited low electrical conductivities and poor device stability, in contrast to p-type semiconductors, which have been...

Lactone Backbone Density in Rigid Electron‐Deficient Semiconducting Polymers Enabling High n‐type Organic Thermoelectric Performance

“…The two‐dimensional scattering patterns and in‐ and ‐out‐of‐plane line cuts are illustrated in Figure 3. All three polymers showed nominally similar scattering patterns in line with the previously reported analogues, though with diminished degrees of lamellar scattering [13a, 14a] . As shown in 2D GIWAXS, all three polymers show a strong isotropic amorphous scattering ring centered near 1.4 Å‐1, with lamellar stack (h00) and π–π stack (010) scattering present both in‐ and out‐of‐plane.…”

n‐Type Rigid Semiconducting Polymers Bearing Oligo(Ethylene Glycol) Side Chains for High‐Performance Organic Electrochemical Transistors

“…Comparisons of similar conformationally locked polymers showed improved 2D transport (OFET) in predominantly face on textured films, and improved 3D transport (bulk molecular doped) in mixed face-on and edge-on textured films. [19] Additionally, peak width estimates of the coherence length of the p-stacking show that PgNaN p-stack ordering extended for 30-75 % greater distances than that of PgNgN, which could be a contributing factor to improved charge transport PgNaN.…”

Acceptor–acceptor-type conjugated polymer semiconductors

“…The structures of A-A-type DPP-based polymers for OFETs. shallowing of LUMO [104]. In any cases, this series of polymers all show long wavelength NIR absorption with air stable electron transport.…”

“…When linking repeat units with carbon-carbon double bonds instead of single bonds based on IID-based homopolymer derivatives, the series of C15-C20 [81,104] were synthesized by aldol condensation like C14. The polymer backbones are locked into a complete rigid conjugated conformation, which can effectively eliminate the rotation and twist between the conjugated units, and the non-covalent interaction can make the main chain in the IID polymer flatter, resulting in improved charge transport.…”

“…Third, the bis-oxindole monomer is replaced with a more electron-withdrawing bis-lactone to synthesize an alternating lactam-lactone copolymer, lowering the LUMO and HOMO levels of the polymer. This method can make the l e of C19 and C19* higher than that of C15 and the size of the aromatic core does not need to be improved [104]. The reason why the performance of C20 is worse than that of C19 is that the decrease in the density of electron-withdrawing lactone units and the increased twist in the backbone by increasing the size of the aryl ring bring a weaker and isotropic p-stacking, and lead to deepening of HOMO and Fig.…”