Polymer light emitting diodes and organic solar cells towards ito free devices and high efficiency devices using electrochemically synthesized polymers /

Hızalan Özsoy, Gönül
In this study, polymer based solar cells and polymer based light emitting diodes were constructed. In the third and fourth chapters of this study, effect of terminal units and effect of molecular weight on electroluminescence and photovoltaic properties were investigated. Triphenyl end capped polymer P1 based PLED shows luminance value of 10411cd/m2 at 8.5V whereas benzene end capped polymer P2 based PLED has the peak luminance value of 14583cd/m2 at 8V. P2 based photovoltaic devices exhibited superior performance. The best performance device based on P2 achieved a power conversion efficiency (PCE) of 4.11 % with a current density (Jsc) of 6.59 mA/cm2, an open-circuit voltage (Voc) of 0.99 V, and a fill factor (FF) of 0.63. In the fifth chapter, electrochemically synthesized polymers were used in polymer solar cell applications for the first time in literature. P3HT, P3EHT, P3OT, P3DecT and P3DHT were synthesized via electrochemical means. P3EHT based solar cells showed the highest performance. PCE of 2.03% was obtained with a Jsc value of 5.10mA/cm2, Voc value of 0.83V, FF value of 0.48 Ternary solar cells comprising P3EHT, PTB7 and PC71BM was fabricated. PCE value of 6.50 % were achieved with a VOC of 0.72V, JSC of 14.60 mA/cm2 and a FF of 0.62. In the last part of this study, ITO free polymer solar cell and PLED characterizations were carried out. Instead of ITO, Ag nanowires were used as the anode materials in polymer solar cell and polymer light emitting diode applications. 1.13% PCE value was achieved with a VOC of 0.53V, JSC of 4.99mA/cm2 and FF of 0.43 with the device structure of glass/Ag nanowire /P3HT:PC71BM/ LiF /Al. 2625cd/m2 luminance value was obtained with P2 incorporated electroluminescent device with a lower turn on voltage than the one for the ITO based device.


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Yaşa, Mustafa; Toppare, Levent Kamil; Department of Polymer Science and Technology (2017)
Donor-Acceptor (D-A) type conjugated polymers are very popular for potential applications such as organic light emitting diodes, solar cells, electrochromic devices and organic field effect transistors. In literature, cyclopentadithiophene and its derivatives are commonly used electron donor units for organic solar cells. The incorporation of selenium atom into polymer backbone results in low band gap polymers as compared to sulfur and oxygen counterparts. In this study, selenophene containing conjugated po...
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Öklem, Gülce; Günbaş, Emrullah Görkem; Department of Polymer Science and Technology (2017)
DPP-based conjugated polymers are recently used in organic light emitting diodes, electrochromic devices, organic field effect transistor and organic solar cell applications. Their advantageous properties, such as broad optical absorption in Near Infra Red (NIR) region, high charge carrier mobility and good film forming ability make them an excellent choice for generation of highly efficient solar cells. In this thesis, using donor-acceptor approach (D-A) we aimed to synthesize novel polymers with furan bas...
Contact resistivity analysis of different passivation layers via transmission line method measurements
Kökbudak, Gamze; Turan, Raşit; Yerci, Selçuk; Department of Micro and Nanotechnology (2017)
Crystalline silicon (c-Si) homojunction solar cells constitute over 90% of the current photovoltaic market. Although the standard solar cells are cost effective and easy to process, their efficiency potential is unfortunately limited. Currently, more innovative cell concepts appeared with their high efficiency potential coupled with low costs. Since the recombination at surfaces and under metal contacts is one of the major obstacles against high conversion efficiencies, surface passivation has primary impor...
Syntheses of functional materials for organic photovoltaic and electrochromic device applications
Varlıoğlu, Figen; Günbaş, Emrullah Görkem; Department of Polymer Science and Technology (2017)
Thienothiophene based moities are widely investigated for organic solar cell applications. In this study, after synthesizing 2-ethylhexyl 4,6-dibromothieno [3,4-b]thiophene-2-carboxylate successfully, copolymerization with commercially available donor 4-(2-ethylhexyl)-2,6-bis(trimethylstannyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole, DTPy, was performed via Stille coupling. At each step, Nuclear Magnetic Resonance (NMR) Spectroscopy were performed for structural analysis. Cyclic voltammogram was used for investig...
Imaging solar cells using terahertz waves
Kayra, Seda; Altan, Hakan; Department of Physics (2011)
In this thesis, Terahertz Time-Domain spectroscopy (THz-TDS) was used in order to measure the electrical properties of silicon solar cells. The advantage of THz-TDS is that it allows us to measure the electrical properties without electrical contacts. In order to perform these measurements, a reflection based system was constructed and the changes in the peak amplitude in the time-domain under a, 450mW 808 nm continuous wave laser source were measured. The solar cell that was used in this thesis was manufac...
Citation Formats
G. Hızalan Özsoy, “Polymer light emitting diodes and organic solar cells towards ito free devices and high efficiency devices using electrochemically synthesized polymers /,” Ph.D. - Doctoral Program, Middle East Technical University, 2017.