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The electron transport layer (ETL) is a crucial part in perovskite solar cells (PSC) as it specifically governs the charge extraction at the perovskite/ETL interface. In this study, methylammonium lead iodide-based PSCs with an n-i-p structure were fabricated and modified by adding colloidal TiO2 into the mesoporous TiO2 film as ETL. The effect of the colloidal TiO2 addition on the PSC performance was investigated for ETL comprising different types of TiO2 particles, i.e. P25 and anatase TiO2. Despite producing lower performance than the PSC made with commercial paste, the power conversion efficiency of the PSCs could be improved with the introduction of colloidal TiO2 solution. An optimum condition was observed depending on the type of TiO2 particle, where the best performing device was achieved with colloidal TiO2 of 0.4 and 0.2 mL for P25 and anatase TiO2, respectively. The amount of colloidal TiO2 in samples with P25 overall had less impact than the samples with anatase TiO2.

Dye-sensitized solar cells (DSSC) has been well known as a highly competitive photovoltaic technology owing to its interesting characteristics, such as, low-cost, simple, and convenient to modify both chemically and physically. One way to reduce the production cost of DSSCs is to conduct a structural modification in the form of a monolithic structure by using a single conductive substrate to accommodate both photoelectrode and counter electrode. However, the photovoltaic performance of monolithic DSSCs is typically still lacking compared to its conventional DSSCs counterparts that uses sandwich structure. One of the crucial factors that determine the photovoltaic performance of a monolithic DSSC is its electrolyte. In this work, the performance of monolithic DSSCs were studied through modifications of the electrolyte component. Two types of commercial liquid electrolytes that have different chemical properties were used and combined into various compositions, and the resulting DSSCs performances were compared. The stability of the monolithic cells was also monitored by measuring the cells repeatedly under the same condition. The result showed that during the first measurement the highest performance with a power conversion efficiency of 1.69% was achieved by the cell with a higher viscosity electrolyte. Meanwhile, the most stable performance is shown by the cell containing lower viscosity electrolyte, which achieved an efficiency of 0.66% that measured on day 35.

Research about mesoporous TiO2 as an electron transport layer in perovskite solar cell has been done to obtain the best fabricated cell’s performance. In this research, the concentrations of opaque and transparent TiO2 nanoparticle were varied, in order to optimize the TiO2 mesoporous electron transport layer in FTO/CL-TiO2/MS-TiO2/Perovskite/P3HT/Ag perovskite-based solar cell. Morphological, optical, and electrical characteristics of TiO2 layers were investigated using scanning electron microscopy (SEM), four-point probe (FPP), and UV-Vis spectroscopy. The influences of those characteristics in solar cell performance were analyzed by using illumination of sun simulator with a light intensity of 500 W/m2. The results showed that transparent TiO2 has a higher conductivity and transmittance compared to the opaque TiO2. The concentration of TiO2 solutionin1:17 ratio resulted in higher electrical performance in both the transparent and opaque TiO2 layer. The best perovskite solar cell performance with PCE of 0.37% was achieved from the sample using TiO2 transparent layer with a concentration of 1:7 ratio.

Since invented for the first time, researchers in the world were focusing on how to increase the efficiency of dye-sensitized solar cells (DSSC) and reduce of the fabrication cost. Monolithic type of DSSC is one of the best solutions to reduce the fabrication cost due to the elimination of one of transparent conductive oxide (TCO) substrate. In this study, DSSC monolithic was fabricated layer by layer by using screen printing method. There are three layers that printed in each cell namely TiO2, ZrO2, and carbon before being injected with electrolytes. The geometrical structure of DSSC was varied to find the highest performance. From the I-V characteristics and incident photon-to-current efficiency (IPCE) characterization shows the highest efficiency is 0.137% and the highest conversion of photons to current occurs at around 510 nm wavelength, for a structure which has ZrO­2 layer not crosses over the no-FTO area, while TiO2 layer half crosses the no-FTO area, this is most likely caused by the imperfection of the ZrO2layer.

Monolithic dye-sensitized solar cells (DSSC) offer the prospect of lower material cost and require a simpler manufacturing process compared with conventional DSSC. Fabricated on a single fluorine tin oxide (FTO) glass substrate consists of a nanoporous TiO2 photoanode layer, a ZrO2 spacer layer, a carbon counter electrode layer, a dye, and an electrolyte. The spacer layer on the monolithic DSSC serves as electrolyte storage and insulating layer to separate between photoanode and counter electrode. Zirconia is often used as a spacer because it has high temperature resistant properties, high dielectric constant and adhesive as an insulator that has band gap between 5-6 eV. The effects of the thermal treatment of zirconia layer as a spacer electrolyte on the performance of monolithic DSSC have been investigated. The cell’s performance increases with the sintering temperature as well as indicated by the decreased in particle size and increased in quantum efficiency in the absorption region of the titania layer. Co-sintering treatment tends to drastically reduce cell’s performance. The highest performance was obtained at a temperature sintering of 500o C with an PCE of 0.22%, Isc = 0.16 mA and Voc = 0.71 V.

Monolithic design is one of the most promising dye-sensitized solar cell (DSSC) architectures to develop, because it allows the elimination of one conductive substrate and offers the possibility for printing layer-by-layer of the materials that made up its structure. In this study, titanium dioxide-based monolithic type DSSCs were fabricated on a single fluorine-doped transparent oxide coated glass with TiO2 as photoanode and porous ZrO2 as spacer. The type of the carbon material used as the composite paste for the counter electrode was varied to see the effect on the solar cell efficiency. Four-point probes measurement revealed that the resistivity of the carbon layer synthesized using activated carbon exhibited slightly higher conductivity with a sheet resistance of 10.70 Ω/sq and 11.09 Ω/sq for activated carbon and carbon nanopowder, respectively. The efficiency of DSSC that uses activated carbon as counter electrode was higher (i.e. 0.221%) than the DSSC with carbon nanopowder (i.e. 0.005%). The better performance of DSSC with activated carbon as a counter electrode was due to its better conductivity and higher surface area compared to those of carbon nanopowder.

Hybrid polymer solar cell has privilege than its conventional structure, where it usually has structure of (ITO/PEDOT:PSS/Active Layer/Al). In humid environment the PEDOT:PSS will absorb water and hence can easily etch the ITO. Therefore it is necessary to use an alternative method to avoid this drawback and obtain more stable polymer solar cells, namely by using hybrid polymer solar cells structure with an inverted device architecture from the conventional, by reversing the nature of charge collection. In this paper we report the results of the fabrication of inverted bulk heterojunction polymer solar cells based on P3HT:PCBM as active layer, utilizing ZnO interlayer as buffer layer between the ITO and active layer with a stacked structure of ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag. The ZnO interlayer is formed through short route, i.e. by dissolving ZnO nanoparticles powder in chloroform-methanol solvent blend rather than by sol-gel process. Based on the measurement results on electrical characteristics of inverted polymer solar cells under 500 W/m2 illumination and AM 1.5 direct filter at room temperature, cell with annealing process of active layer at 110 °C for 10 minutes results in higher cell performance than without annealing, with an open-circuit voltage of 0.21 volt, a short-circuit current density of 1.33 mA/cm2 , a fill factor of 43.1%, and a power conversion efficiency of 0.22%. The low cell’s performance is caused by very rough surface of ZnO interlayer.

Dye-sensitized solar cells (DSSC) are widely developed due to their attractive appearance and simple fabrication processes. One of the challenges that arise in the DSSC fabrication involves high material cost associated with the cost of conductive substrate. DSSC with monolithic configuration was then developed on the basis of this motivation. In this contribution, titanium dioxide-based monolithic type DSSCs were fabricated on a single fluorine-doped transparent oxide coated glass using porous ZrO2 as spacer. Herein, the catalytic material for the counter-electrode was varied using carbon composite and platinum in order to analyze their effect on the solar cell efficiency. Four-point probe measurement revealed that the carbon composite exhibited slightly higher conductivity with a sheet resistance of 9.8 Ω/sq and 10.9 Ω/sq for carbon and platinum, respectively. Likewise, the photoconversion efficiency of the monolithic cells with carbon counter-electrode almost doubled the efficiency of the cells with platinum counter-electrode. Our results demonstrate that carbon could outperform the performance of platinum as catalytic material in monolithic DSSC.

Optical waveguides are important for guiding lightwave from a place to other places. Propagation and insertion losses of the optical waveguides should be considered to be in low values. Recently, optical waveguides with circular structures, which are optical fibers, are used widely for guiding lightwave in long-distance optical communication with very low propagation and insertion losses. Simultaneously, optical waveguides with planar structure are also developed for short distance communication in optical devices. We have reported design and analysis of the planar optical waveguides. In this paper, fabrication of planar optical waveguides using a polyimide material on thin silicon dioxide combined with the silicon substrate is reported. The polyimide material is used for the core of the optical waveguides. The silicon dioxide located on the silicon substrate and the air is used for cladding of the optical waveguides. Fabrication of the optical waveguides such as oxidation, photoresist coating, masking, ultra-violet exposure, and etching was done. The fabricated optical waveguides were characterized physically using a standard microscope and scanning electron microscope (SEM). The fabrication processes and characterization results are reported and discussed in detail.

This research reports on a fabrication of polymer solar cells based on blends of two widely used polymeric semiconductors i.e. poly(2-methoxy-5-(3,7-dimethyloctyloxy)-para phenylene vinylene) (MDMO-PPV) and the soluble fullerene C60 derivative [6,6 phenyl C61-butyric acid methyl ester] (PCBM). The devices were fabricated on an indium tin oxide (ITO) coated glass substrate. After cleaned and dried, a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in H2O was spin coated onto the freshly prepared substrate and then dried in a vacuum oven at 120°C for 60 minutes. A blend of MDMO-PPV and PCBM in chlorobenzene was spin coated on the top and dried in a nitrogen ambient at room temperature for 24 hours. The devices were transferred to a sputtering system where an aluminum was coated. Some of the devices then were annealed in a vacuum oven at 60°C for 60 minutes. Finally, the devices were encapsulated by placing a sealant between the back of the devices and glass slides and then cured in a vacuum oven at temperature 100°C for 10 minutes. For characterization, the devices were illuminated with a xenon lamp at the intensity of 27 mW/cm2 and the temperature at approximately 25°C. The influence of the annealing treatment and polymer blends on the photovoltaic performance of the devices was also discussed here. The best performance was obtained from the device with a blend ratio of 1:1 MDMO-PPV/PCBM without annealing treatment. The typical power efficiency was 0.01% with open circuit voltage of 0.347 V, short circuit current of 0.064 mA, and maximum power of 0.006 mW.

Addressing the imperative need to eliminate hazardous lead from the widely used metal halide perovskite photovoltaics (PPVs), the search for efficient and stable lead‐free perovskite alternatives remains pivotal. Herein, a performance analysis of lead‐free, all‐inorganic cesium tin triiodide (CsSnI3)‐based PPVs with a graphene oxide hole transporting layer using solar cell capacitance simulator is presented. Various parameters to optimize the PPV performance, including CsSnI3 layer thickness, defect density, interface defect, parasitic resistances, and working temperature are explored. The optimization process yielded remarkable results, with open‐circuit voltage of 0.87 V, short‐circuit current density of 32.55 mA cm−2, fill factor of 77.59%, and power conversion efficiency of 22.15%. The proposed device structure and parameters not only contribute to the advancement of these experimental works but also offer a novel strategy for the structural optimization of lead‐free PPVs, thereby paving new avenues for future research in this area. [ABSTRACT FROM AUTHOR]

This research aims to analyze the importance of school committees' role and strategies in improving education quality. Through comprehensive analysis, this research identifies the role and strategies of school committees in developing school programs and supporting and inhibiting factors in the implementation process. This research uses a qualitative case study type approach. Data was collected through semi-structured interviews, observation and documentation to determine the role and strategies of influential school committees in efforts to improve school quality. The research results illustrate that the school committee plays an active role as a school partner in supporting school quality improvement initiatives. The strategy implemented by the school committee is carried out through continuous evaluation, recommendations, and raising resources to find problems, take corrective action, and optimize available resources. This research highlights that the success of the school committee's role and strategy will be much more optimal and maximal if it is linked to quality improvements that all parties, both internal and external to the school recognize. This research contributes to advancing school quality improvement methods that can be used and developed in madrasah and schools in the future.