title: Influence of deposition substrate temperature on the morphology and molecular orientation of chloroaluminum phthalocyanine films as well the performance of organic photovoltaic cells.
abstract: The dependence of the morphology of neat chloroaluminum phthalocyanine (ClAlPc) films on substrate temperature (Tsub) during deposition is investigated by variable angle spectroscopic ellipsometry (VASE), x-ray diffraction (XRD), and atomic force microscopy (AFM) to obtain detailed information about the molecular orientation, phase separation, and crystallinity. AFM images indicate that both grain size and root mean square (RMS) roughness noticeably increase with Tsub both in neat and blend films. Increasing Tsub from room temperature to 420 K increases the horizontal orientation of the ClAlPc molecules with an increase of the mean molecular tilt angle from 60.13° (300 K) to 65.86° (420 K). The UV-vis absorption band of the corresponding films increases and the peak wavelength slightly red shifts with the Tsub increase. XRD patterns show a clear diffraction peak at Tsub over 390 K, implying the π-stacking of interconnected ClAlPc molecules at high Tsub. Planar and bulk heterojunction (BHJ) photovoltaic cells containing pristine ClAlPc films and ClAlPc:C60 blend films fabricated at Tsub of 390 K show increases in the power conversion efficiency (ηPCE) of 28% (ηPCE = 3.12%) and 36% (ηPCE = 3.58%), respectively, relative to devices as-deposited at room temperature. The maximum short circuit current in BHJs is obtained at 390 K in the Tsub range from 300 K to 450 K.
authors.affiliation: Key Laboratory of Advanced Display and System Applications, Shanghai University, Ministry of Education, P.O.B. 143, 149 Yanchang Rd., Shanghai 200072, People's Republic of China. Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan.
authors.forename: Yan-Qiong
authors.initials: YQ
authors.lastname: Zheng
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Yang
authors.forename: Takeshi
authors.initials: T
authors.lastname: Komino
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhang
authors.forename: Zixing
authors.initials: Z
authors.lastname: Wang
authors.forename: Wenhong
authors.initials: W
authors.lastname: Pu
authors.forename: Changzhu
authors.initials: C
authors.lastname: Yang
authors.forename: Chihaya
authors.initials: C
authors.lastname: Adachi
mesh_terms: D065966:Absorption, Physicochemical; D006358:Hot Temperature; D007211:Indoles / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods*; D009942:Organometallic Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; C044797:chloroaluminum phthalocyanine