Yaşa, Mustafa
There are several studies on organic solar cells based on conjugated polymers in literature, and various new materials are being designed. The Donor-Acceptor approach has been the most common approach for designing and synthesizing conjugated polymers. In this study, thienopyrroledione bearing conjugated polymers were synthesized via Stille and Suzuki polycondensation reactions. In the first part of this thesis, the polymers obtained via Stille polycondensation were employed to fabricate organic solar cells (OSCs). Both non-fullerene and fullerene-based devices were fabricated. The best non-fullerene-based device performed a power conversion efficiency of 7.94%, whereas the best fullerene-based device performed 7.62%. In the second part, one of the polymers obtained via Stille polycondensation was used to fabricate biosensors for catechol detection. The biosensor exhibited linearity between 1.25 and 175 μM catechol, with a LOD of 1.23 μM and sensitivity of 737.4 μA.mM−−2. In the third part, the polymers obtained via Suzuki polycondensation were examined to see the effect of a second acceptor unit through random polymerization, and the study revealed that the introduction of a selenophene moiety decreased the optical band gaps of the polymers whereas the introduction of a second acceptor moiety increased the optical band gaps. As another emerging technology for energy conversion, Perovskite solar cells have been the point of attraction. Therefore, the last part covers syntheses of a series of chalcogenophene containing molecules to be employed as organic cations for surface treatment of 3D perovskite films in the fabrication of Perovskite solar cells. The best perovskite solar cell device constructed with the utilization of one of the molecules exhibited a power conversion efficieny of 22.43%.


Ciftpinar, Emine Hande; Turan, Raşit; Yerci, Selçuk; Department of Micro and Nanotechnology (2022-4-22)
The design and development of high-efficiency interdigitated back contact (IBC) solar cells have been studied within the scope of this thesis. Developing a totally industry-compatible, lithography-free, high-throughput process flow for IBC cell fabrication was the main motivation of the thesis. For this, a detailed simulation study was conducted using Quokka 2 software to optimize the rear side cell geometry and understand the effect of bulk and layer properties on the device performance. After determining ...
Dual-band high-frequency metamaterial absorber based on patch resonator for solar cell applications and its enhancement with graphene layers
Ustunsoy, Mehmet Pasa; Sabah, Cumali (2016-12-05)
In this paper, a dual-band high-frequency metamaterial absorber based on patch resonator is designed and analyzed for solar cells. In order to obtain a metamaterial absorber, metal-semiconductor-metal layers are combined. The results of the designed structure are shown in the infrared and visible ranges of solar spectrum. Structural parameters and dimensions of the device have a significant importance on the performance of the designed absorber. The simulations are carried out with full-wave electromagnetic...
New DPP and Selenophene based NIR Absorbing Polymers for Organic Solar Cell Applications
Günbaş, Emrullah Görkem; Toppare, Levent Kamil; Oklem, Gulce (2018-07-06)
The broad spectrum of sunlight which spans from 300 nm to 1200 nm cannot be effectively utilized in organic solar cells since most organic polymers have absorption between 300 ve 800 nm range. Recently coppolymers from diketopyrrolopyrrole (DPP) and simple donors such as thiophene and furan was shown to achieve absorption maxima around 800 nm. Here we shown that DPP coupled with selenophene pushes the absorption even futher and a polymer with absorption maxima at 830 nm (absorption onset 930 nm) could be at...
Photovoltaic Properties of Poly(Triphenylamine-Thiazolo[5,4-d] Thiazole) Copolymer Dye in Bulk-Hetorojunction Organic Solar Cells
Olgun, Ugursoy; Gulfen, Mustafa; HIZALAN, Gonul; Çırpan, Ali; Toppare, Levent Kamil (2017-04-01)
In this study, the photovoltaic properties of poly(triphenylamine-thiazolo[5,4-d]thiazole) alternating copolymer dye in bulk heterojunction polymer solar cells were examined. The copolymer is a red colored dye material with high thermal stability, good solubility and low-band gap energy. The band gap energy of the polymer was determined as 1.36 eV. The conductivity of the polymer thin film was measured as 1.5x10(-5) S/cm. The polymer solar cells were fabricated using the different ratios of the blends of th...
Benzodithiophene and selenophene bearing polymer for inverted organic solar cell applications
Toppare, Levent Kamil; Yaşa, Mustafa; Göker, Seza; Udum, Yasemin; Günbaş, Emrullah Görkem; Çırpan, Ali (null; 2018-07-06)
Inverted organic solar cells have advantages over conventional organic solar cells. Most important advantage is the improved stability of inverted solar cells. In this study, benzodithiophene, quinoxaline and selenophene bearing conjugated polymer was used as donor material in inverted solar cell applications. Device performances were investigated with the device configuration of ITO/ ZnO/ polymer:PC71BM/ MoO3/ Ag. In order to improve device performance, polymer PCBM ratio, active layer thickness, annealing...
Citation Formats
M. Yaşa, “CONJUGATED POLYMERS AND ORGANIC CATIONS FOR OPTOELECTRONIC APPLICATIONS,” Ph.D. - Doctoral Program, Middle East Technical University, 2022.