Browsing by Author "Ersoz, Mustafa"

Now showing 1 - 5 of 5

Citation - WoS: 1
Citation - Scopus: 1
Advancing Perovskite Solar Cells: Inorganic CCTS Hole-Transporting Material for Enhanced Efficiency and Stability
(Elsevier, 2025) Sari, Fahriye; Ozel, Sultan Suleyman; Sarilmaz, Adem; Ozel, Faruk; Kus, Mahmut; Ersoz, Mustafa
One of the most effective methods for generating renewable energy is the efficient conversion of photons into electrical energy using environmentally sustainable materials. In recent years, the integration of chalcogenide materials, which exhibit graphene-like semiconducting properties and high charge carrier mobility, into perovskite solar cells (PSCs) has garnered significant attention for enhancing the performance, stability, and ecofriendly nature of these devices. In this study, Cu2CoSnS4 (CCTS) nanocrystals were synthesized and utilized as a fully inorganic hole transport layer (HTL) in inverted PSCs. Devices incorporating 6 vol% CCTS achieved a power conversion efficiency (PCE) of 10.07 %, and retained 93 % of their initial efficiency after 720 h under inert storage conditions, without encapsulation. This demonstrates a notable improvement in stability compared to conventional PEDOT: PSS-based devices. The optimized CCTS HTL provided better energy level alignment, reduced moisture ingress, and enhanced charge transport. These findings indicate that CCTS is a promising inorganic HTL candidate for efficient and stable PSCs.
Citation - WoS: 2
Citation - Scopus: 4
Dye-Sensitized Sepiolite Clay as Natural Scaffolds for Visible Light Driven Photocatalytic Hydrogen Evolution
(Pergamon-Elsevier Science Ltd, 2025) Acar, Eminegul Genc; Akyildiz, Yigit Osman; Kuru, Talha; Yenel, Esma; Aslan, Emre; Ersoz, Mustafa; Patir, Hatay
Natural clay minerals are increasingly used as superior support materials for various photocatalysts due to their excellent adsorption capacity, negative surface charge, suitable thermal/chemical stability, large specific surface area, and strong surface reactivity, resulting in low agglomeration and suppression of charge recombination. However, they are still insufficient for photocatalysis due to their low efficiency. Therefore, sensitization of clay minerals with dyes to improve the efficiency and specificity of catalysts is considered a promising route for photocatalytic applications. In this work, the effect of dye sensitization on visible light-driven photocatalytic water splitting of microfibrous sepiolite scaffolds as natural photocatalyst supports was investigated for the first time by using various xanthene dyes (eosin Y, rhodamine B and eryhtrosine B (ErB)) and triethanolamine as photosensitizers and sacrificial agents, respectively, in the absence and presence of platinum as a co-catalyst. The clay/dye system was characterized using various techniques such as X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy and energy dispersive X-rays. Sep/ErB photocatalysts produced the highest amount of hydrogen among the other Sep/dye scaffold systems because they act as an effective matrix by preventing nanoparticle aggregation and promoting electron transfer due to their excellent crystal structures and physicochemical properties.
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.
Citation - WoS: 2
Citation - Scopus: 2
Polyoxometalate-Doped Hole Transport Layer To Boost Performance of Mapbi3-Based Inverted-Type Perovskite Solar Cells
(Amer Chemical Soc, 2025) Buyukcelebi, Sumeyra; Kazici, Mehmet; Torlak, Yasemin; Kus, Mahmut; Ersoz, Mustafa
This study delves into the examination of the efficiency, stability, and repeatability of perovskite solar cells (PSCs), a focal point in contemporary photovoltaic (PV) technologies. The aim is to address the challenges encountered in PSCs. To achieve this goal, Ge-doped polyoxometalate, a structure of significance in recent molecular electronics, was employed as a dopant in the hole transport layer (HTL). The study investigated alterations in the conductivity, improvements in efficiency, and changes in PV parameters. The utilization of PEDOT/PSS doped with a maximum of 2% GePOM resulted in an average efficiency increase of 27% in PSCs compared with the reference. Moreover, enhancements in stability and repeatability were also noted. Comparatively, the reference PSC operated at an efficiency of 11.18%, while PSCs incorporating 2% GePOM into PEDOT/PSS as the HTL exhibited a notable increase in the efficiency, reaching 14.22%. Furthermore, the champion device exhibited an observed fill factor value of 0.74, a short-circuit current density (J sc) value of 19.78 mA/cm2, and an open-circuit voltage (V oc) value of 0.98 V. Consequently, noteworthy enhancements have been noticed in the PV parameters of PSCs with the introduction of GePOM doping.
Citation - WoS: 5
Transfer of Cvd-Graphene on Real-World Surfaces in an Eco-Friendly Manner
(Amer Chemical Soc, 2023) Yılmaz, Kurtuluş; Gürsoy, Mehmet; Sakalak, Huseyin; Ersoz, Mustafa; Karaman, Mustafa
Here we report a one-step and all-dry transfer method for transfer of chemical vapor deposited graphene (CVD-graphene) on different application surfaces using pressure sensitive adhesive (PSA) material as the transfer medium, which is deposited on the application surface by the initiated CVD (iCVD) method in the form of a thin film. The as-deposited PSA film is a copolymer of acrylic acid and ethylhexyl acrylate, in which the relative amount of each component was shown to be a determining factor for the proper adjustment of the adhesive force required for the adhesion-based transfer process. With the help of the thin PSA film on the real-world application surface, graphene transfer was achieved with ease and at high quality by just peeling off the copper substrate, where CVD-graphene was initially deposited. With the all-dry and eco-friendly transfer procedure outlined in this study, it was possible to transfer graphene to a flexible large-area PET substrate (10 cm x 10 cm) on which higher conductivity values were obtained from the I-V experiments as compared with the graphene transferred using the classical wet approach.