Low Threshold Microlasers Based on Organic-Conjugated Polymers

Conjugated polymers have emerged as ideal organic laser materials for the excellent optoelectrical properties and facile processability. During a typical lasing process, resonator configurations with specific geometry are essential to provide optical feedback and then amplified light. Herein, we summarized the geometry and working mechanism of several typical resonator configurations formed with conjugated polymers. Meanwhile, recent advances in fabrication techniques and lasing performance are also discussed to provide new ideas for the design and optimization of microcavity geometries. Followed by the advances of practical applications in fields of laser sensing, bioimaging, and laser illumination/display, we make a summary of the existing bottlenecks and future perspectives of electrically driven organic lasers toward laser display and illumination.

Magnetic Behavior of an Iron Gluconate/Polyaniline Composite

Oxidative polymerization conducted the synthesis of polyaniline in the presence of iron gluconate in the water. Iron gluconate is present in the resulting polyaniline (PANI). The PANI composite exhibited multiple signals in electron spin resonance, including half-field resonance of multiple spin states, the center-field resonance of polarons as radical cations in conducting polymer, and a signal from a defect in the main chain. Infrared (IR) absorption spectroscopy measurements confirmed the chemical structure of the PANI composite. The composite exhibits the mixed magnetism of PANI as a conducting polymer and Fe ions in the composite according to superconducting interference device (SQUID) measurements. Combining organic-conjugated polymers and inorganic materials can result in a unique magnetism.

A review on the development of conjugated polymer-based textile thermoelectric generator

Thermoelectric (TE) materials based on conjugated/conductive polymers can directly convert heat into electricity, and thus found promising applications in energy scavenging and cooling technologies. The performance of these thermoelectric materials is governed by different parameters like the nature of the material, thermal stability, electrical conductivity, Seebeck coefficient, and thermal conductivity. Although the traditional inorganic semiconductor materials such as PbTe (Lead Telluride), Bi2Te3 (Bismuth Telluride), SiGe (Silicon-Germanium), SnSe (Tin Selenide), and Skutterudite (CoAs2) are giving high performance, they have some inherent limitations, such as poor processability, toxicity, rare availability, and high cost of manufacturing. Whereas, organic conjugated polymers such as polyacetylene (PA), polyaniline (PANi), Poly(3-hexylthiophene) (P3HT), polypyrrole (PPy), poly 3,4-ethylenedioxythiophene (PEDOT), etc. have low cost of synthesis, light in weight, low toxicity and better processibility. Organic textile thermoelectric generators (T-TEG) can be prepared by in-situ polymerization of the conjugated polymers onto textile substrates. This article reviews the preparation, design and performance of these T-TEGs. Various approaches and scopes of improvement of efficiency of the thermoelectric effect of the T-TEGs are discussed. Various potential applications of the T-TEG in different fields are also described.

A tied Fermi liquid to Luttinger liquid model for nonlinear transport in conducting polymers

Organic conjugated polymers demonstrate great potential in transistors, solar cells and light-emitting diodes, whose performances are fundamentally governed by charge transport. However, the morphology–property relationships and the underpinning charge transport mechanisms remain unclear. Particularly, whether the nonlinear charge transport in conducting polymers is appropriately formulated within non-Fermi liquids is not clear. In this work, via varying crystalline degrees of samples, we carry out systematic investigations on the charge transport nonlinearity in conducting polymers. Possible charge carriers’ dimensionality is discussed when varying the molecular chain’s crystalline orders. A heterogeneous-resistive-network (HRN) model is proposed based on the tied-link between Fermi liquids (FL) and Luttinger liquids (LL), related to the high-ordered crystalline zones and weak-coupled amorphous regions, respectively. The HRN model is supported by precise electrical and microstructural characterizations, together with theoretic evaluations, which well describes the nonlinear transport behaviors and provides new insights into the microstructure-correlated charge transport in organic solids.

A tied Fermi liquid to Luttinger liquid model for the explanation of nonlinear transport in conducting polymers

Organic conjugated polymers demonstrate great potential in the transistor, solar cell and light-emitting diodes. The performances of those devices are fundamentally governed by charge transport within the active materials. However, the morphology-property relationships and the underpinning charge transport mechanism in polymers remain unclear. Particularly, whether the nonlinear charge transport in doped conducting polymers, i.e., anomalous non-Ohmic behaviors at low temperature, is appropriately formulated within non-Fermi liquid picture is not clear. In this work, via varying crystalline degrees of samples, we carried out systematic investigations on the charge transport nonlinearity in conducting polymers. Possible charge carriers’ dimensionality was discussed with experiments when varying the molecular chain’s crystalline orders. A heterogeneous-resistive-network (HRN) model was proposed based on the tied link between Fermi liquids (FL) and Luttinger liquids (LL), related to the high-ordered crystalline zones and weak-coupled amorphous regions, respectively. This mesoscopic HRN model is experimentally supported by precise electrical and microstructural characterizations, together with theoretic evaluations. Significantly, such model well describes the nonlinear transport behaviors in conducting polymers universally and provides new insights into the microstructure-correlated charge transport in organic conducting/semiconducting systems.