Title
EFFICIENT FLUORESCENT AND PHOSPHORESCENT OLEDs BY SPIN COATING TECHNIQUE AND A NEW ANODE BASED ON CONDUCTIVE PEDOT:PSS
Author
Luis Abraham Lozano Hernández
Contributor
José_Luis Maldonado (Thesis Adviser)
Access level
Open Access
Subjects
Summary or description
"Fluorescent and phosphorescent Organic Light Emitting Diode (OLED) devices were fabricated by solution process and optimized. From their basic characterization (J-V-L curves, electroluminescence spectra) external quantum efficiency (EQE) was calculated. Two small molecule, carbazole derivatives (CZ-1 and CZ-2), previously reported and used for OLEDs showed very good luminances (~ 4000 cd/m2) and current densities (< 200 mA/cm2) resulting in a high EQE (9.5 %). Likewise, fluorescent OLEDs based in the new polymer PF-2F presented an acceptable performance even on a simple architecture with a good EQE (2.6 %), photoluminescence quantum yield (PLQY) about 1 and excellent properties of processability. The influence of its CF3 group in the optical, chemical, electronic and mechanical properties in OLEDs was determined.
Also, a new family of three fluorescent oligomers (BT-F32, BT-F42 and BT-F52) with excellent properties in solution, high PLQY (~1) and highly luminescent, were used in simple and multilayer OLEDs achieving a very high luminance (29 499 cd/m2). These oligomers have different chain lengths, which influence the device luminance, efficiency and their lifetime. Lifetime was monitored and the stretched exponential decay (SED) model was used in order to obtain the device half-life (LT50). Also, phosphorescent devices, based on a host/guest system (PVK:Ir(ppy)3), were prepared, the influence of the electron transport layer (ETL) into the electron/hole ratio was analyzed.
By using a new proposed method, a PEDOT:PSS anode was developed and applied in rigid and flexible substrates, with low sheet resistance (40 Ω/□) and acceptable transmittance (> 85%). This new proposed method consists in volume evaporation, in which basically the loss of water induces closeness among the conductive fractions of PEDOT. This PEDOT:PSS anode easy of fabricating following an economical procedure could be applied not just in OLEDs but in other optoelectronic devices such as organic photovoltaic cells (OPVs), perovskite solar cells (PeSCs), etc."
Publish date
August 21, 2020
Publication type
Doctoral thesis
Publication version
Published Version
Information Resource
Format
application/pdf
Language
English
Coverage
León, Guanajuato
Audience
Librarians
Students
Researchers
General public
Citation suggestion
Lozano-Hernández, (2020). "Efficient fluorescent and phosphorescent OLEDs by spin coating technique and a new anode based on conductive PEDOT:PSS". Tesis de Doctorado en Ciencias (Óptica). Centro de Investigaciones en Óptica, A.C. León, Guanajuato, México. 106 pp.
Source repository
REPOSITORIO INSTITUCIONAL DEL CIO
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