Browsing by Author "Kurukavak, Cisem Kirbiyik"

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Citation - WoS: 3
Citation - Scopus: 2
Dual- and Triple- Hetero-Atom Carbon Dots as Novel Additives for the Engineering of Defects Passivation To Boost Performance of Perovskite Solar Cells
(Springer, 2025) Kurukavak, Cisem Kirbiyik; Tok, Mutahire; Yurdakul, Merve; Kus, Mahmut
Methylammonium lead iodide (MAPbI3)-based perovskite solar cells (PSCs) offer highly efficient photovoltaics. However, several disadvantages such as poor stability and possibility of defect formation reducing film quality have restricted its commercialization. In this work, we reported the synthesis of dual- and triple-hetero-atom-doped carbon quantum dots (CQDs) via hydrothermal method and their effect of use as additive on the performance of PSCs. The boron (B) and phosphorous (P)-doped CQDs (B,P-CQDs), sulphur (S) and P-doped CQDs (S,P-CQDs), and B, S, and P-doped CQDs (B,S,P-CQDs) additives were described. Since these CQDs have many functional groups including hydroxyl (-OH), they can easily interact with Pb ions leading to the formation of PbO, as well as interaction with methyl ammonium ions. A reduced halide vacancy density and an increased nucleation energy of perovskite enhance crystal sizes and charge transfer. The passivation of surface defects reduces non-radiative recombination and ion migration, which plays an important role in photodegradation of the MAPbI3 films. Herein, the introduction of S,P-CQDs improved power conversion efficiency (PCE) from 10 to 15% and current density (Jsc) from 14.4 to 23.6 mA cm-2. PSCs added with dual- and triple-hetero-atom-doped CQDs showed narrower efficiency distribution in comparison to the control devices.
Citation - WoS: 3
Citation - Scopus: 2
Effect of Hetero-Atom Doping on the Structure and Optical Properties of Carbon Quantum Dots for the Sensitive Detection of Heavy Metal Ions
(Wiley, 2025) Kurukavak, Cisem Kirbiyik; Tok, Mutahire; Toprak, Aysegul; Yurdakul, Merve; Ersoz, Mustafa
Metal pollution in water sources due to modernization is a human health and environmental problem. Therefore, the highly fluorescent boron- and nitrogen-doped and nitrogen-doped carbon quantum dots (B,N-CQDs and N-CQDs, respectively) were synthesized and investigated to be used as a fluorescence sensor for metal ion detection. In this study, the synthesized B,N-CQDs and N-CQDs had an average size of 4-6 nm and 3-4 nm, respectively. The B,N-CQDs presented high sensitivity as 0.0090, 0.0086 and 0.0091 units per micromolar for Cr3+, Cu2+ and Fe2+, respectively, whereas the N-CQDs showed sensitivity as 0.0047, 0.0102, 0.0095 and 0.0121 units per micromolar for Cr3+, Cu2+, Fe2+ and Ni2+, respectively. In the concentration range of 10-80 mu M, the detection limits of B,N-CQDs and N-CQDs were found to be in the range of 13.9-65.5 mu g/L and 14.9-38.3 mu g/L, respectively. The result of the study clearly indicates that B,N-CQDs and N-CQDs can be seen as metal ion sensing devices with high sensitivity and low cost.
Spray Coating Versus Spin Coating of Titanium Dioxide as Electron Transfer Layer for Organic Solar Cells
(Springer, 2025) Yilmaz, Tugbahan; Buyukbekar, Alihan; Kurukavak, Cisem Kirbiyik; Kus, Mahmut
In this study, spray coating and spin coating methods for the titanium oxide (TiO2) layer used as the electron transfer layer (ETL) were compared to examine the performance parameters of organic solar cells. Despite the fact that there is no major change in the VOC value, with VOC measured at 0.589 V for the spray-coated device and 0.548 V for the spin-coated device, the device performance parameters of the device fabricated with TiO2 layer sharply increased, with the current density-voltage (J-VSC), fill factor (FF), and power conversion efficiency (PCE) values obtained by the spray coating method. We demonstrate that spray-coated c-TiO2 layers achieve a higher PCE of 2.92% compared to 2.32% for spin-coated devices. The PCE of the solar cell using TiO2 formed by spray coating is 25% higher than the device obtained by spin coating.
Citation - Scopus: 1
Use of Cspbx3 Nanocrystals as an Additive in Organic Solar Cell for Efficiency Improvement
(Elsevier, 2025) Kurukavak, Cisem Kirbiyik; Tok, Mutahire
Here, we aimed to investigate the dependence of organic solar cells (OSCs) performance on the CsPbX3 perovskites nanocrystals (PNCs). The effect of presence of CsPbX3 (X = Cl, Br, and I) NCs in photoactive layer was studied using various characterization techniques. UV-Vis spectroscopy and XRD patterns of P3HT:PCBM thin films showed that the light harvesting, crystallinity and phase separation increased by the introducing PNCs, which improved the electrical properties. The AFM images supported the improved crystallinity of P3HT and homogeneous structure of photoactive layer. OSCs with the configuration of ITO/PEDOT:PSS/P3HT: PCBM: PNCs/LiF/Al were fabricated. The PNCs incorporation resulted to efficiency enhancement from 1.75 % to 2.88 % (P3HT:PCBM - CsPbBr3). The increase in efficiency was strongly related to the improved current density (J(sc)) (10.75 mA cm(- 2)) and open-circuit voltage (V-oc) (0.598 V).