title: Temperature-Dependent Evolution of Poly(3-Hexylthiophene) Type-II Phase in a Blended Thin Film.
abstract: The structure of P3HT in P3HT:PCBM films is examined on a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (
  PSS) substrate subjected to cryo-cooling to low temperature (-143 °C) followed by gradual heating to 50 °C. The behavior of these systems is examined in the absence and presence of an Al electrode on top of the P3HT:PCBM film. At temperatures below -10 °C, only the type-I phase of P3HT is observed. However, the type-II phase of P3HT starts to form near -10 °C, in both the presence and absence of the Al layer. In the system without an Al layer, the type-II phase disappears at 30 °C, but this phase persists to 50 °C in the presence of the Al layer. Concomitant with the formation of the type-II phase, a 1:3 ordered P3HT type-II (1/3,0,0) superlattice peak emerged. The type-II domains tend to form near the Al electrode layer and show a higher degree of alignment than the type-I crystals.
authors.affiliation: Department of Organic Material Science and Engineering, Pusan National University, Busan, 609-755, South Korea.
authors.forename: Si Woo
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Department of Organic Material Science and Engineering, Pusan National University, Busan, 609-755, South Korea.
authors.forename: Hee-Sung
authors.initials: HS
authors.lastname: Keum
authors.affiliation: Department of Organic Material Science and Engineering, Pusan National University, Busan, 609-755, South Korea.
authors.forename: Han Seong
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Organic Material Science and Engineering, Pusan National University, Busan, 609-755, South Korea.
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Physics, Soongsil University, Seoul, 126-743, South Korea.
authors.forename: Kwangseok
authors.initials: K
authors.lastname: Ahn
authors.affiliation: Department of Physics, Soongsil University, Seoul, 126-743, South Korea.
authors.forename: Dong Ryeol
authors.initials: DR
authors.lastname: Lee
authors.affiliation: Pohang Accelerator Laboratory, POSTECH, Pohang, 790-784, South Korea.
authors.forename: Je Han
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Pohang Accelerator Laboratory, POSTECH, Pohang, 790-784, South Korea.
authors.forename: Hyun Hwi
authors.initials: HH
authors.lastname: Lee
mesh_terms: D003460:Crystallization; D004952:Esters / Q000737:chemistry; D053838:Scattering, Small Angle; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013876:Thiophenes / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004952:Esters; D012997:Solvents; D013876:Thiophenes; C507295:poly(3-hexylthiophene)
keywords: P3HT; alignment; polymorph; solvent mixture; type-II phase