ABSTRACT
Transparent and conductive electrodes (TCEs) are essential for various optoelectronic and photovoltaic applications, but they often require expensive and complex fabrication methods. In this paper, a unique low-cost, eco-friendly, and scalable method of fabricating TCEs using spray-coated carbon ink is investigated. Firstly the carbon particles used for this process underwent a size reduction from 20 microns to 0.96 microns via ball milling. Then ink was prepared by mixing graphite powder (for conductivity), ethyl cellulose (for viscosity), and toluene (for solubility) with different weight-per-volume ratios (w/v) of 5%, 10%, and 15%. The TCEs were fabricated by spray coating the ink onto glass substrates using an airbrush. The sheet resistance (Ω sq-1) and transparency (%) of the TCEs were measured by a digital multimeter (DMM) probe method and a UV-vis spectrophotometer, respectively. The sheet resistance of the TCEs decreased linearly from 60 to 20 Ω sq-1, while the transparency decreased exponentially from 37.18% to 18.88% as the ink concentration increased from 5% to 15% w/v. This paper also reports the reflectance and absorbance values for each ink concentration. The results demonstrate that spray-coated carbon ink TCEs achieve sheet resistance and transparency values of 20 Ω sq-1 and 18.88%, respectively, with low-cost and eco-friendly materials and methods, which are desirable for optoelectronic and photovoltaic applications. These TCEs can play an important role as electrodes in semi-transparent perovskite cells enhancing their stability and overall efficiency.
ABSTRACT
In the current study, waste marble powder was utilized to produce lightweight fired clay bricks and in the treatment of flue gases. Marble waste powder used in clay bricks and flue gas treatment was collected from local marble processing plants, and its chemical composition was analyzed using energy-dispersive X-ray analysis and X-ray fluorescence. Clay bricks were produced in local fired clay brick kiln by partial replacement (10-40%) of clay with calcined and uncalcined waste marble powder. The temperature in the firing zone of the kiln was 1000-1100 °C. Clay brick properties such as compressive strength, bulk density, porosity, and water absorption were analyzed. Results show that the porosity of clay bricks increases with an increase in marble waste percentage, and due to an increase in porosity, water absorption of clay bricks also increases, while compressive strength and bulk density decrease. Clay bricks with 10% uncalcined marble waste and 20% calcined marble waste satisfy the required Turkish and European compressive strength standard. Marble waste decreases the concentration of sulfur dioxide and particulate matter in flue gases. There is up to 43 and 65% reduction in the concentration of sulfur dioxide and particulate matters, respectively, in flue gases, after treatment with marble waste. The addition of marble waste to clay bricks is an effective and economical solution for waste marble powder management. Furthermore, it can be used for the treatment of flue gases from brick kilns before its addition to clay bricks.
