Papers by Maqsood Ali Mughal
Titanium dioxide (TiO 2 ) has long been considered a model photoanode material for electrolysis o... more Titanium dioxide (TiO 2 ) has long been considered a model photoanode material for electrolysis of water using solar energy. A number of studies have looked into the synthesis methods to optimize physical as well as chemical properties of titania photoanodes. Electric field assisted anodic oxidation of titanium (Ti) for fabrication of titania photoanodes is a relatively new synthesis technique. This paper presents a systematic study of this technique by varying anodization parameters. The current-time behavior of Ti anodization was also studied. The current-voltage (I-V) characteristic of these samples was measured under dark and illumination conditions. The electrode fabricated using 20 Volts for 20 minutes demonstrated the best performance among all the samples tested. The photocurrent density obtained under visible radiation was 0.528 mA/cm 2 . This study will assist in design and fabrication of new electrodes for photoelectrolysis using a material that is photoactive, stable, corrosion resistant, and cost effective.
ELSEVIER, Jul 31, 2015
Recent progress with indium (III) sulfide (In2S3)-buffered thin film solar cells (TFSC) was brief... more Recent progress with indium (III) sulfide (In2S3)-buffered thin film solar cells (TFSC) was briefly reviewed. In2S3 has emerged as a promising low-hazard buffer (or window) material, and has proven to improve the properties of the solar cells, while reducing toxicity. Various deposition techniques have been employed to synthesize In2S3 films on different types of substrates. Until now, atomic layer deposition (ALD) and ionic layer gas atomic reaction (ILGAR) techniques have been the two most successful, yielding maximum energy conversion efficiencies up to 16.4% and 16.1%, respectively. The impact of varied deposition parameters upon the In2S3 film properties and performance of cadmium (Cd)-free solar cells has been outlined. A comparative/operational analysis (solar cell efficiencies above 9% reported for cell area ≤ 1cm2) of various buffer layers used in two primary types of TFSC technology: chalcopyrite (CIS/CIGS)- and CdTe-based solar cells was also performed to measure the progress of In2S3 compared to its counterparts.
Properties of electrodeposited semiconductor thin films are dependent upon the electrolyte compos... more Properties of electrodeposited semiconductor thin films are dependent upon the electrolyte composition, plating time, and temperature as well as the current density and the nature of the substrate. In this study, the influence of the electrodeposition parameters such as deposition voltage, deposition time, composition of solution, and deposition temperature upon the properties of In2S3 films was analyzed by the Taguchi Method. According to Taguchi analysis, the interaction between deposition voltage and deposition time was significant. Deposition voltage had the largest impact upon the stoichiometry of In2S3 films and deposition temperature had the least impact. The stoichiometric ratios between sulfur and indium (S/In: 3/2) obtained from experiments performed with optimized electrodeposition parameters were in agreement with predicted values from the Taguchi Method. The experiments were carried out according to Taguchi orthogonal array L27 () design of experiments (DOE). Approximately 600 nm thick In2S3 films were electrodeposited from an organic bath (ethylene glycol-based) containing indium chloride (InCl3), sodium chloride (NaCl), and sodium thiosulfate (Na2S2O3·5H2O), the latter used as an additional sulfur source along with elemental sulfur (S). An X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDS) unit, and scanning electron microscope (SEM) were, respectively, used to analyze the phases, elemental composition, and morphology of the electrodeposited In2S3 films.
Within the last few years, there has been notable progress in understanding the growth mechanisms... more Within the last few years, there has been notable progress in understanding the growth mechanisms of semiconductor thin films for photovoltaic (PV) applications. Electrodeposition continues to be a complex deposition technique that can lead to regions of low quality (for example, cracks) in films. Such cracks can form porous zones on the substrate and diminish the heterojunction interface quality of a PV cell. In this paper, electrodeposition of In2S3 films was systematically and quantitatively investigated by varying electrodeposition parameters including bath composition, current density, deposition time, and deposition temperature. Their effects upon the morphology, composition, and film growth mechanism were studied with the help of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and digital imaging analysis (using fracture and buckling analysis software). In addition, the effect of different annealing treatments (200°C, 300°C, and 400°C in air) and coated glass-substrates (Mo, ITO, and FTO) upon the properties of the In2S3 films was analyzed. Furthermore, the Taguchi/Design of Experiments (DOE) Method was used to determine the optimal electrodeposition parameters in order to improve the properties.
In 2 S 3 has received attention as an alternative to CdS as the buffer layer in heterojunction so... more In 2 S 3 has received attention as an alternative to CdS as the buffer layer in heterojunction solar cells. Although having a bandgap of 2.0 eV relative to 2.5 eV for CdS, the lower toxicity and environmental impact of indium relative to cadmium, and significant photosensitivity, compel ongoing research [1]. Indium sulfide thin films were deposited onto molybdenum-coated glass (SiO 2 ) substrates by electrodeposition from organic baths (ethylene glycolbased) containing indium chloride (InCl 3 ), sodium chloride (NaCl), and sodium thiosulfate (Na 2 S 2 O 3 .5H 2 O), the latter used as an additional sulfur source along with elemental sulfur (S). The Taguchi method was used to optimize the deposition paramters so as to minimize non-uniformity, cracks, and improper stoichiometry. The measured performance characteristics (molar ratio (In:S) and crack density) for all of the In 2 S 3 films were calculated to analyze the effect of each deposition factor (deposition voltage, deposition temperature, composition of solution, and deposition time) involved in the electrodeposition process by calculating the sensitivity (signal to noise, S/N, ratios).
In 2 S 3 has received attention as an alternative to CdS as the buffer layer in heterojunction s... more In 2 S 3 has received attention as an alternative to CdS as the buffer layer in heterojunction solar cells. Although having a bandgap of 2.0 eV relative to 2.5 eV for CdS, the lower toxicity and environmental impact of indium relative to cadmium, and significant photosensitivity, compel ongoing research [1]. Indium sulfide thin films were deposited onto molybdenum-coated glass (SiO 2) substrates by electrodeposition from organic baths (ethylene glycol-based) containing indium chloride (InCl 3), sodium chloride (NaCl), and sodium thiosulfate (Na 2 S 2 O 3 .5H 2 O), the latter used as an additional sulfur source along with elemental sulfur (S). The Taguchi method was used to optimize the deposition paramters so as to minimize non-uniformity, cracks, and improper stoichiometry. The measured performance characteristics (molar ratio (In:S) and crack density) for all of the In 2 S 3 films were calculated to analyze the effect of each deposition factor (deposition voltage, deposition temperature, composition of solution, and deposition time) involved in the electrodeposition process by calculating the sensitivity (signal to noise, S/N, ratios).
Electrodeposition can enable stoichiometric control of deposited samples through variation of ele... more Electrodeposition can enable stoichiometric control of deposited samples through variation of electroplating potential. We demonstrate an in-situ technique for deposit analysis and stoichiometric control by interspersing periods of open-circuit during deposition. Opening the circuit in an organic Cu-In-S plating bath allows greater incorporation of Cu, In, and/or S into deposited films, based upon the open-circuit voltage the film/electrolyte interface is allowed to achieve. With the same deposition potential, samples can be made to vary from highly Cu-rich to highly In-rich through selection of an appropriate open-circuit voltage limit.
2014 IEEE 40th Photovoltaic Specialist Conference (PVSC), 2014
Within the last few years, there has been notable progress in understanding the growth mechanisms... more Within the last few years, there has been notable progress in understanding the growth mechanisms of semiconductor thin films for photovoltaic (PV) applications. Electrodeposition continues to be a complex deposition technique that can lead to regions of low quality (for example, cracks) in films. Such cracks can form porous zones on the substrate and diminish the heterojunction interface quality of a PV cell. In this paper, electrodeposition of In 2 S 3 films was systematically and quantitatively investigated by varying electrodeposition parameters including bath composition, current density, deposition time, and deposition temperature. Their effects upon the morphology, composition, and film growth mechanism were studied with the help of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and digital imaging analysis (using fracture and buckling analysis software). In addition, the effect of different annealing treatments (200 • C, 300 • C, and 400 • C in air) and coated glass-substrates (Mo, ITO, and FTO) upon the properties of the In 2 S 3 films was analyzed. Furthermore, the Taguchi/Design of Experiments (DOE) Method was used to determine the optimal electrodeposition parameters in order to improve the properties. 11 12 13 14 15 16 17 18 19 20
We report research on electrodeposition of indium sulfide films, with In2S3 a less hazardous alte... more We report research on electrodeposition of indium sulfide films, with In2S3 a less hazardous alternative to CdS buffer layers in solar cells. Numerous organic and aqueous/organic electrolytes of InCl3, NaCl, and 978-1-4244-9965-6/11/$26.00 ©2011 IEEE
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Papers by Maqsood Ali Mughal