3,4-Disubstituted Polyalkylthiophenes for High-Performance Thin-Film Transistors and Photovoltaics
摘要:
We demonstrate that poly(3,4-dialkylterthiophenes) (P34ATs) have comparable transistor mobilities (0.17 cm(2) V-1 s(-1)) and greater environmental stability (less degradation of on/off ratio) than regioregular poly(3-alkylthiophenes) (P3ATs). Unlike poly(3-hexylthiophene) (P3HT), P34ATs do not show a strong and distinct pi-pi stacking in X-ray diffraction. This suggests that a strong pi-pi stacking is not always necessary for high charge-carrier mobility and that other potential polymer packing motifs in addition to the edge-on structure (pi-pi stacking direction parallel to the substrate) can lead to a high carrier mobility. The high charge-carrier mobilities of the hexyl and octyl-substituted P34AT produce power conversion efficiencies of 4.2% in polymer:fullerene bulk heterojunction photovoltaic devices. An enhanced open-circuit voltage (0.716-0.771 eV) in P34AT solar cells relative to P3HT due to increased ionization potentials was observed.
A process including:
creating a composition composed of a liquid and a self-organizable polymer at least partially dissolved in the liquid, resulting in dissolved polymer molecules;
reducing the solubility of the dissolved polymer molecules to induce formation of structurally ordered polymer aggregates in the composition;
depositing a layer of the composition including the structurally ordered polymer aggregates; and
drying at least partially the layer to result in a structurally ordered layer, wherein the structurally ordered layer is part of an electronic device and the structurally ordered layer exhibits increased charge transport capability.
Polythiophenes of the formula
1
wherein R and R′ are side chains; A is a divalent linkage; x and y represent the number of unsubstituted thienylene units; z represents the number of groups, and wherein the sum of x and y represents the number of groups; m represents the number of segments; and n represents the degree of polymerization.
A thin film transistor wherein the semiconductor layer is prepared by a process including:
creating a composition comprising a liquid and a self-organizable polymer at least partially dissolved in the liquid, resulting in dissolved polymer molecules;
reducing the solubility of the dissolved polymer molecules to induce formation of structurally ordered polymer aggregates in the composition;
depositing a layer of the composition including the structurally ordered polymer aggregates; and
drying at least partially the layer resulting in the structurally ordered semiconductor layer, wherein the structural order of the semiconductor layer increases the charge transport capability of the semiconductor layer.
A process including:
creating a composition composed of a liquid and a self-organizable polymer at least partially dissolved in the liquid, resulting in dissolved polymer molecules;
reducing the solubility of the dissolved polymer molecules to induce formation of structurally ordered polymer aggregates in the composition;
depositing a layer of the composition including the structurally ordered polymer aggregates; and
drying at least partially the layer to result in a structurally ordered layer, wherein the structurally ordered layer is part of an electronic device and the structurally ordered layer exhibits increased charge transport capability.
Fully non-fused electron acceptors (FNEAs) have shown a promising prospect for commercial applications of organic solar cells (OSCs) due to their simple structures and low costs. Herein, two terthiophene-based NFEAs 3T-1 and 3T-2 were exploited from a single thiophene ring as the starting material. Octyl substituted 3T-1 exhibits strong crystallinity, poor miscibility, and forms large aggregates when