P- and N-dopable ambipolar bulk heterojunction thermoelectrics based on ladder-type conjugated polymers

Abstract

Ambipolar bulk heterojunction polymer thermoelectrics was demonstrated for the first time using the classic n-type poly(benzimidazobenzophenanthrolinedione) ladder polymer (BBL) and the new p-type 6H-pyrrolo[3,2-b:4,5-b′]bis[1,4]benzothiazine ladder polymer (PBBTL). The blend films...

Balancing Solubility and Thermoelectric Performance in π-Extended Poly(benzimidazoanthradiisoquinolinedione) Ladder-Type Conjugated Polymer

“…Ladder-type conjugated polymers (LCPs) are a promising class of conjugated polymers where the polymer backbone is composed of double-stranded fused-ring structure that limits its torsional rotation. Because of this, LCPs usually have highly rigid coplanar conformations that exhibit excellent mechanical properties, as well as thermal and chemical stability. − Coplanar polymer backbones can extend intrachain delocalization that facilitate intrachain charge transfer and are also beneficial for strong π–π interactions that promote interchain charge transport. − These unique advantages render ladder-type conjugated polymers as highly promising in organic electronic devices including organic thin film transistors (OTFTs), , organic electrochemical transistors (OECTs), , organic thermoelectrics (OTEs), − lithium-/sodium-ion batteries (LIBs/SIBs), − and supercapacitors. , However, the greatest challenge for LCPs synthesis and characterization is insolubility, either due to cross-linking or high molecular weight. The latter becomes an issue when the π-system in each repeating unit becomes too big.…”

Molecular doping principles in organic electronics: fundamentals and recent progress

“…Demand for n-type dopants for efficient and stable doping is increasing since the device applications such as OLEDs, [26][27][28][29] complementary circuits, [30][31][32] and thermoelectric generation all simultaneously require both p-and n-doping. [33][34][35] Even though various materials and methods were introduced for ntype doping of OSCs such as (i) using alkali metals, [36][37][38] (ii) molecular compounds with significantly shallow HOMO, [39][40][41][42][43] and (iii) air-stable precursor molecules that can donate an electron to the matrix material in the deposited film, [44][45][46] we focus here on the latter two due to the doping stability of alkali metals, 47) One of the earliest works on n-type molecular dopants with low IE is bis(cyclopentadienyl)-cobalt(ΙΙ) (cobaltocene, CoCp 2 ), which is a strong reducing agent with an ionization energy of about 4 eV, and an n-type dopant capable of shifting the Fermi level of OSC by 0.5 eV to the conduction band. 43) In addition, interfacial doping of CoCp 2 reduced the charge injection barrier at the Au/PEDOT:PSS interface, demonstrating decent current enhancement that is comparable to that of p-doping of N,N′-diphenyl-N,N′-bis(1-naphthyl) −1,1′-bi-phenyl-4,4′diamine (α-NPD) with F 4 TCNQ.…”

Distinguishing thermoelectric and photoelectric modes enables intelligent real-time detection of indoor electrical safety hazards

“…These include: thermoelectric materials, which generate electrical signals in response to temperature changes; thermoresponsive deformation materials, which undergo structural changes with temperature variation; thermochromic materials, which exhibit color changes with temperature fluctuations; and thermistor materials, which display changes in electrical resistance based on temperature alterations. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] However, relying solely on a single temperature-sensing material restricts the ability to accurately identify and monitor potential electrical hazards and health risks in the presence of complex indoor temperature a College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China. E-mail: iouydu@szu.edu.cn, chengm@szu.edu.cn b College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China † Electronic supplementary information (ESI) available.…”