Euis Sustini | Institut Teknologi Bandung (original) (raw)
Papers by Euis Sustini
Journal of King Saud University - Science
We described the average traffic congestion in several populous cities around the world from a ne... more We described the average traffic congestion in several populous cities around the world from a new concept, namely landscape percolation. The ratio of the residential area size to road width is a fundamental parameter that controls the traffic congestion. We have compared the model with data extracted from several populous cities around the world (directly from Google Earth images) and demonstrated very consistent results. The criterion for a city landscape that makes a city is considered as congested or less congested has been identified. The model also explains remarkably well the consistency of the measured data with various reports on congestion levels (such as the recognized Tomtom congestion level or Numbeo traffic index) of some populous cities around the world. These findings may help in designing new cities or redesigning the infrastructure of congested cities, for example for deciding what is the maximum size of the residential area and how width the roads are. This work also shows the similarity of the problem in conducting composite (electric current flow), brine transport between icebergs (fluid flow), and traffic (vehicle flow).
Institute of Metals and Materials Australasia, 1991
arXiv: Applied Physics, 2018
We report the development of graphite-based solar cells using a simple method and low cost materi... more We report the development of graphite-based solar cells using a simple method and low cost materials. Suspension of graphite powder in mineral water was simply dropped onto the surface of fluorine-doped tin oxide glass (FTO) to form a thick film. Surprisingly, using mineral waters greatly improved the efficiency of the solar cell to reach the highest efficiency of 6.97%. Due to some minerals contained, the mineral water induced the development of fibrous structure between the graphite particles which is assumed to play a role as a bridge for the photoexcited electrons to quickly move to the electrode and suppress recombination with holes. This efficiency is very attractive when considering the materials used to develop the solar cell are all low cost. Economically this may challenge the present high efficiency semiconductor-based solar cells. We achieved the high efficiency by manipulating the cell fill factor through optimizing the ion concentration in PVA.LiOH polymer electrolyte....
Telah dihitung rapat keadaan polyasetilen dengan ketakmurnian lithium melalui perhitungan fungsi ... more Telah dihitung rapat keadaan polyasetilen dengan ketakmurnian lithium melalui perhitungan fungsi Green. Potensial dihitung dari fungsi gelombang yang bersangkutan. Dalam perhitungan ini simetri diperhitungkan, tapi vibrasi diabaikan.
The efforts to fabricate a solar cell cheaper than DSSC type have been increasingly developed. A ... more The efforts to fabricate a solar cell cheaper than DSSC type have been increasingly developed. A new design of solar cell using cheap TiO2 as photon absorber and PVA.LiOH as hole transport medium has been continously evolved, including the attempt to alter LiOH as main material of polymer electrolyte. For this purpose, an inexpensive solar cell using PVA.NaCl polymer electrolyte as a hole transport medium replacing PVA.LiOH has been successfully fabricated. A suspension of TiO2 was initially deposited on Fluorine Tin Oxide using droplet method followed by heating at 200 °C for two hours. The content of NaCl was varied from 10, 21, 32 and 43% compared to the content of PVA to achieve the best efficiency. 0.04% efficiency was gained using 32% of NaCl content. To get a better performance of the solar cell, TiO2/graphite composite was used as photon absorbing materials. Graphite powder was inserted into the suspension of TiO2 and varied from 10, 20, 30 and 40% based on the TiO2 content....
In this paper, we present a review on the development in modeling of transmittance and tunneling ... more In this paper, we present a review on the development in modeling of transmittance and tunneling current through a high-K dielectric gate stack of a metal-oxide- semiconductor (MOS) capacitor by considering the coupling of transverse and longitudinal energies of an electron represented by an electron phase velocity in the gate and anisotropic masses. In order to obtain the electron transmittance and tunneling current, Airy- and exponential wavefunctions were utilized as analytical approaches. A transfer matrix method (TMM) was used as a numerical approach as a benchmark to find the best analytical approach in calculating the transmittance and tunneling current. It was shown that the Airy wavefunctions approach was a better analytical expression to calculate the transmittance and tunneling current. Furthermore, the tunneling currents computed under Airy wavefunction approach were compared to the measured ones to examine the model. It was shown that the calculated tunneling currents a...
Thin film GaSb have been grown using vertical MOCVD from precursor TMGa and TDMASb at various gro... more Thin film GaSb have been grown using vertical MOCVD from precursor TMGa and TDMASb at various growth condition. The growth temperatures and V/III ratio were in the range of 475oC – 525oC and 0.7 – 1.2, respectively. The growth layers were characterized using XRD and SEM, the best surface morphology so far was obtained at the growth temperature of 500oC and V/III ratio of 0.99
We observed the conformation of threads that free released from different altitudes. We also expl... more We observed the conformation of threads that free released from different altitudes. We also explore the effect of wetting liquid on the conformation developed. When released from an altitude, the thread conformation changes when free falling and reaches the stable conformation (identified by a constant end-to-end distance) after fall over a period of time. We identified that the conformation of the threads replicated the conformation of long polymer chains. Therefore, we applied a two-dimensional random walk model to explain the stable conformation where the thread length is treated as the random walk time (number of polymer segment). A two-dimensional random walk model was used since during free fall, the conformation is assumed to develop on the horizontal plane. Surprisingly, we get the scaling power that is exactly similar to the scale power of two dimensional random (walk). By fitting how end-to-end distance changes with time, we obtain an equation that is exactly similar to m...
Journal of Mathematical and Fundamental Sciences, 2001
Abstract. Quantum Dots is a nano structured materials, which is an interesting object for fundame... more Abstract. Quantum Dots is a nano structured materials, which is an interesting object for fundamental study as well as for applications. Quantum Dots has been used for optoelectronic devices, such as fast detectors and for lasers. In this paper we report preliminary results of the preparation of quantum dots of GaSb in our laboratory. These dots are prepared by self-organized growth by MOCVD, using Trymethylgalium and Tridismethylaminoantimonat as metal organic sources and using GaAs as substrate. The results are studied by Scanning Electron Microscope. We propose further characterization of these quantum dots. Studi Mengenai Titik Kuantum GaSb Sari. Quantum Dot adalah material yang mempunyai struktur nano, yang merupakan objek untuk penelitian fundamental maupun untuk penerapannya. Dalam makalah ini dilaporakan hasil-hasil yang pertama yang kita peroleh dalam pembuatan Quantum Dot dari GaSb dalam laboratorium kami. Quantum Dot ini telah ditumbuhkan dengan menggunakan penumbuhan ya...
IOP Conference Series: Materials Science and Engineering
The present work focused on the effects of TiO2 in degrading organic wastewater. Technical TiO2 o... more The present work focused on the effects of TiO2 in degrading organic wastewater. Technical TiO2 of anatase crystalline phase was used. TiO2 photocatalyst showed a powerful result in destroying organic effluent. Spray coating was conducted to immobilize the TiO2 particles onto the plastic buffer followed with heat-treatment process. As a result, 30 mL of 25 mg L−1 methylene blue (MB) used in the photocatalyst test was sucessfully degraded after 4 hours of irradiation. Repetitive use of the TiO2 films still has a great photodecomposition ability of removing 99% of the organic contaminant after 5 times use.
Jurnal Fisika
Kajian mengenai karakteristik sifat mekanik benang merupakan hal yang sifatnya sederhana namun pe... more Kajian mengenai karakteristik sifat mekanik benang merupakan hal yang sifatnya sederhana namun penting dilakukan demi berkembangnya penelitian mengenai serat dan benang. Pada penelitian ini digunakan dua jenis benang di pasaran yakni benang wol dan benang kasur. Karakterisasi meliputi kekuatan benang, elongasi, tenacity dan modulus Young. Berdasarkan hasil uji tarik didapatkan nilai kekuatan, elongasi dan tenacity dari benang. Nilai kekuatan benang wol berkisar 1269,09gram-1551,32gram. Dari kurva hasil uji tarik dapat diestimasi nilai modulus Young dari benang wol yang ada di pasaran yaitu 295 MPa-439 MPa. Sedangkan untuk hasil karakterisasi benang kasur di pasaran didapatkan bahwa benang mampu menahan beban maksimum 4794,12 gram-5895,45gram dan nilai modulus Young dari benang kasur didapatkan nilai 389,7MPa-495,29 MPa.
Jurnal Fisika dan Aplikasinya
Dalam tulisan ini film tipis semikonduktor GaSb telah ditumbuhkan dengan metoda MOCVD vertikal pa... more Dalam tulisan ini film tipis semikonduktor GaSb telah ditumbuhkan dengan metoda MOCVD vertikal pada tekanan 50 torr di atas subtsrat SI GaAs(100). Film mempunyai type p dengan permukaan yang cukup homogen serta orientasi film didominasi (200). Film yang ditumbuhkan pada temperatur 520 oC dengan rasio V/III=1 mempunyai mobilitas 68,57 cm 2 /Vs dan konsentrasi 1,9 x 10 18 cm −3. Metal Semikonduktor Metal (MSM) Al-pGaSb telah dibuat menggunakan dua metoda, yaitu metoda sederhana evaporasi dengan luas kontak 0,02 cm 2 dan metoda UV litografi dengan luas kontak 0,009 cm 2. MSM bersifat ohmik kontak dengan resistansi spesifik Rc menurun terhadap luas kontak yang digunakan.
AIP Conference Proceedings, 2010
The utilization of solid-waste, especially leaves-waste is one of interesting research of environ... more The utilization of solid-waste, especially leaves-waste is one of interesting research of environmental field. One of them is making a composite using polyvinyl acetate (PVAc) polymer as binder (matrix) and silica nanoparticles as reinforcement (filler) to improve the strength of composite-produced. Those raw materials preliminary were mixed by simple mixing with varied compositions and then hot-pressed at 36 MPa and 100 qC for 20 minutes. From compressive strength test, it was found that composite with composition 7:8 of PVAc and leaves-waste had maximum compressive strength, i.e. 57.60 MPa. It was also that the enhancement of strength due to PVAc fraction (w/w) increasing is a percolation behavior, even though its mathematical explanation has not been performed. Into composition of maximum strength above, silica with average size is 74 nm then was added to improve the strength and found that at silica weight fraction of 0.79 (%w/w), the composite had optimum compressive strength, i.e. 70.5 MPa, or increased up to 22.4% of that without silica. The final compressive strength was very comparable to some building goods such as sandstones and bricks. The composite density was also measured and obtained that it was about 0.9 g/cm
Key Engineering Materials
In this paper, an analytical expression of the electron spin-dependent tunneling current through ... more In this paper, an analytical expression of the electron spin-dependent tunneling current through a potential barrier by applying a bias voltage was investigated. An Airy wavefunction was applied to derive the transmittance through the barrier by considering a zinc-blende material, which depends on the spin states indicated as ‘up’ and ‘down’. The obtained transmittance was employed to compute the polarization and spin-dependent tunneling current. The spin-dependent tunneling current was then observed at various bias voltages and temperatures. It was shown that the spin-polarized current increases as the bias voltage increases. It was also shown that the increase of temperature enhances the spin-dependent tunneling current.
Progress in Natural Science: Materials International
IOP Conference Series: Materials Science and Engineering
Nata de coco is a bacterial cellulose produced by Acetobacter xylinum in the process of fermentin... more Nata de coco is a bacterial cellulose produced by Acetobacter xylinum in the process of fermenting coconut water. It is renowned for its high fiber content. The chewiness of nata de coco is proportional to the fiber content. There are many brands of nata de coco available in the market. Six different brands are included in this study. The mechanical strengths have been evaluated using a Universal Testing Machine. Based on the tensile test results, the lowest Young's modulus is 3 MPa, attributed to the brand labeled as F as the most elastic nata de coco among the six brands. The degree of elasticity of nata de coco also corresponds to the sugar content. Further, the optical properties have been observed using a UV/Vis Spectrometer. Clearer nata de coco yields higher transmittance value. Meanwhile, the turbidity commensurate the nitrogen content.
IOP Conference Series: Materials Science and Engineering
We have successfully fabricated solar cell using flexible counter electrode of graphite powder. T... more We have successfully fabricated solar cell using flexible counter electrode of graphite powder. TiO 2 /graphite suspension was simply poured onto heated Fluorine Tin Oxide (FTO) substrate and kept heated at 200 o C for 2 hours. PVA.LiOH polymer electrolyte was employed as a positive charge transfer medium. The counter electrode was made of graphite powder which is manually deposited on transparent plastic using tube-shaped metal which its surface covered with tissue of 2 mm thick. Graphite powder was deposited by straight motion of 20 movements for one coating or one layer. The same activity was repeated on the stacked film to increase the conductivity of the film. Resistivity and transmittance measurement of the film was performed by four-point probe method and UV-Vis equipment respectively. The film thickness and 2-D porosity were measured using an electronic microscope and ImageJ software orderly. The film resistivity and transmittance gradually decreased with the increase of coating number and reached the resistivity of 0.35 Ω.cm and transmittance of 5% for 40 times of coating. At the same time, the film thickness was saturated at the 30 times coating and reached the thickness of 9.4 µm. The film 2-D porosity which indicated how well the surface of the film covered the graphite also decreased to reach the film porosity of 18%. The most conductive film (40 times coating) was used as a flexible counter electrode in TiO2/graphite solar cell. The efficiency of this structure was 0.4 %, a reasonable efficiency achievement for a cheap material and easy method used.
Journal of King Saud University - Science
We described the average traffic congestion in several populous cities around the world from a ne... more We described the average traffic congestion in several populous cities around the world from a new concept, namely landscape percolation. The ratio of the residential area size to road width is a fundamental parameter that controls the traffic congestion. We have compared the model with data extracted from several populous cities around the world (directly from Google Earth images) and demonstrated very consistent results. The criterion for a city landscape that makes a city is considered as congested or less congested has been identified. The model also explains remarkably well the consistency of the measured data with various reports on congestion levels (such as the recognized Tomtom congestion level or Numbeo traffic index) of some populous cities around the world. These findings may help in designing new cities or redesigning the infrastructure of congested cities, for example for deciding what is the maximum size of the residential area and how width the roads are. This work also shows the similarity of the problem in conducting composite (electric current flow), brine transport between icebergs (fluid flow), and traffic (vehicle flow).
Institute of Metals and Materials Australasia, 1991
arXiv: Applied Physics, 2018
We report the development of graphite-based solar cells using a simple method and low cost materi... more We report the development of graphite-based solar cells using a simple method and low cost materials. Suspension of graphite powder in mineral water was simply dropped onto the surface of fluorine-doped tin oxide glass (FTO) to form a thick film. Surprisingly, using mineral waters greatly improved the efficiency of the solar cell to reach the highest efficiency of 6.97%. Due to some minerals contained, the mineral water induced the development of fibrous structure between the graphite particles which is assumed to play a role as a bridge for the photoexcited electrons to quickly move to the electrode and suppress recombination with holes. This efficiency is very attractive when considering the materials used to develop the solar cell are all low cost. Economically this may challenge the present high efficiency semiconductor-based solar cells. We achieved the high efficiency by manipulating the cell fill factor through optimizing the ion concentration in PVA.LiOH polymer electrolyte....
Telah dihitung rapat keadaan polyasetilen dengan ketakmurnian lithium melalui perhitungan fungsi ... more Telah dihitung rapat keadaan polyasetilen dengan ketakmurnian lithium melalui perhitungan fungsi Green. Potensial dihitung dari fungsi gelombang yang bersangkutan. Dalam perhitungan ini simetri diperhitungkan, tapi vibrasi diabaikan.
The efforts to fabricate a solar cell cheaper than DSSC type have been increasingly developed. A ... more The efforts to fabricate a solar cell cheaper than DSSC type have been increasingly developed. A new design of solar cell using cheap TiO2 as photon absorber and PVA.LiOH as hole transport medium has been continously evolved, including the attempt to alter LiOH as main material of polymer electrolyte. For this purpose, an inexpensive solar cell using PVA.NaCl polymer electrolyte as a hole transport medium replacing PVA.LiOH has been successfully fabricated. A suspension of TiO2 was initially deposited on Fluorine Tin Oxide using droplet method followed by heating at 200 °C for two hours. The content of NaCl was varied from 10, 21, 32 and 43% compared to the content of PVA to achieve the best efficiency. 0.04% efficiency was gained using 32% of NaCl content. To get a better performance of the solar cell, TiO2/graphite composite was used as photon absorbing materials. Graphite powder was inserted into the suspension of TiO2 and varied from 10, 20, 30 and 40% based on the TiO2 content....
In this paper, we present a review on the development in modeling of transmittance and tunneling ... more In this paper, we present a review on the development in modeling of transmittance and tunneling current through a high-K dielectric gate stack of a metal-oxide- semiconductor (MOS) capacitor by considering the coupling of transverse and longitudinal energies of an electron represented by an electron phase velocity in the gate and anisotropic masses. In order to obtain the electron transmittance and tunneling current, Airy- and exponential wavefunctions were utilized as analytical approaches. A transfer matrix method (TMM) was used as a numerical approach as a benchmark to find the best analytical approach in calculating the transmittance and tunneling current. It was shown that the Airy wavefunctions approach was a better analytical expression to calculate the transmittance and tunneling current. Furthermore, the tunneling currents computed under Airy wavefunction approach were compared to the measured ones to examine the model. It was shown that the calculated tunneling currents a...
Thin film GaSb have been grown using vertical MOCVD from precursor TMGa and TDMASb at various gro... more Thin film GaSb have been grown using vertical MOCVD from precursor TMGa and TDMASb at various growth condition. The growth temperatures and V/III ratio were in the range of 475oC – 525oC and 0.7 – 1.2, respectively. The growth layers were characterized using XRD and SEM, the best surface morphology so far was obtained at the growth temperature of 500oC and V/III ratio of 0.99
We observed the conformation of threads that free released from different altitudes. We also expl... more We observed the conformation of threads that free released from different altitudes. We also explore the effect of wetting liquid on the conformation developed. When released from an altitude, the thread conformation changes when free falling and reaches the stable conformation (identified by a constant end-to-end distance) after fall over a period of time. We identified that the conformation of the threads replicated the conformation of long polymer chains. Therefore, we applied a two-dimensional random walk model to explain the stable conformation where the thread length is treated as the random walk time (number of polymer segment). A two-dimensional random walk model was used since during free fall, the conformation is assumed to develop on the horizontal plane. Surprisingly, we get the scaling power that is exactly similar to the scale power of two dimensional random (walk). By fitting how end-to-end distance changes with time, we obtain an equation that is exactly similar to m...
Journal of Mathematical and Fundamental Sciences, 2001
Abstract. Quantum Dots is a nano structured materials, which is an interesting object for fundame... more Abstract. Quantum Dots is a nano structured materials, which is an interesting object for fundamental study as well as for applications. Quantum Dots has been used for optoelectronic devices, such as fast detectors and for lasers. In this paper we report preliminary results of the preparation of quantum dots of GaSb in our laboratory. These dots are prepared by self-organized growth by MOCVD, using Trymethylgalium and Tridismethylaminoantimonat as metal organic sources and using GaAs as substrate. The results are studied by Scanning Electron Microscope. We propose further characterization of these quantum dots. Studi Mengenai Titik Kuantum GaSb Sari. Quantum Dot adalah material yang mempunyai struktur nano, yang merupakan objek untuk penelitian fundamental maupun untuk penerapannya. Dalam makalah ini dilaporakan hasil-hasil yang pertama yang kita peroleh dalam pembuatan Quantum Dot dari GaSb dalam laboratorium kami. Quantum Dot ini telah ditumbuhkan dengan menggunakan penumbuhan ya...
IOP Conference Series: Materials Science and Engineering
The present work focused on the effects of TiO2 in degrading organic wastewater. Technical TiO2 o... more The present work focused on the effects of TiO2 in degrading organic wastewater. Technical TiO2 of anatase crystalline phase was used. TiO2 photocatalyst showed a powerful result in destroying organic effluent. Spray coating was conducted to immobilize the TiO2 particles onto the plastic buffer followed with heat-treatment process. As a result, 30 mL of 25 mg L−1 methylene blue (MB) used in the photocatalyst test was sucessfully degraded after 4 hours of irradiation. Repetitive use of the TiO2 films still has a great photodecomposition ability of removing 99% of the organic contaminant after 5 times use.
Jurnal Fisika
Kajian mengenai karakteristik sifat mekanik benang merupakan hal yang sifatnya sederhana namun pe... more Kajian mengenai karakteristik sifat mekanik benang merupakan hal yang sifatnya sederhana namun penting dilakukan demi berkembangnya penelitian mengenai serat dan benang. Pada penelitian ini digunakan dua jenis benang di pasaran yakni benang wol dan benang kasur. Karakterisasi meliputi kekuatan benang, elongasi, tenacity dan modulus Young. Berdasarkan hasil uji tarik didapatkan nilai kekuatan, elongasi dan tenacity dari benang. Nilai kekuatan benang wol berkisar 1269,09gram-1551,32gram. Dari kurva hasil uji tarik dapat diestimasi nilai modulus Young dari benang wol yang ada di pasaran yaitu 295 MPa-439 MPa. Sedangkan untuk hasil karakterisasi benang kasur di pasaran didapatkan bahwa benang mampu menahan beban maksimum 4794,12 gram-5895,45gram dan nilai modulus Young dari benang kasur didapatkan nilai 389,7MPa-495,29 MPa.
Jurnal Fisika dan Aplikasinya
Dalam tulisan ini film tipis semikonduktor GaSb telah ditumbuhkan dengan metoda MOCVD vertikal pa... more Dalam tulisan ini film tipis semikonduktor GaSb telah ditumbuhkan dengan metoda MOCVD vertikal pada tekanan 50 torr di atas subtsrat SI GaAs(100). Film mempunyai type p dengan permukaan yang cukup homogen serta orientasi film didominasi (200). Film yang ditumbuhkan pada temperatur 520 oC dengan rasio V/III=1 mempunyai mobilitas 68,57 cm 2 /Vs dan konsentrasi 1,9 x 10 18 cm −3. Metal Semikonduktor Metal (MSM) Al-pGaSb telah dibuat menggunakan dua metoda, yaitu metoda sederhana evaporasi dengan luas kontak 0,02 cm 2 dan metoda UV litografi dengan luas kontak 0,009 cm 2. MSM bersifat ohmik kontak dengan resistansi spesifik Rc menurun terhadap luas kontak yang digunakan.
AIP Conference Proceedings, 2010
The utilization of solid-waste, especially leaves-waste is one of interesting research of environ... more The utilization of solid-waste, especially leaves-waste is one of interesting research of environmental field. One of them is making a composite using polyvinyl acetate (PVAc) polymer as binder (matrix) and silica nanoparticles as reinforcement (filler) to improve the strength of composite-produced. Those raw materials preliminary were mixed by simple mixing with varied compositions and then hot-pressed at 36 MPa and 100 qC for 20 minutes. From compressive strength test, it was found that composite with composition 7:8 of PVAc and leaves-waste had maximum compressive strength, i.e. 57.60 MPa. It was also that the enhancement of strength due to PVAc fraction (w/w) increasing is a percolation behavior, even though its mathematical explanation has not been performed. Into composition of maximum strength above, silica with average size is 74 nm then was added to improve the strength and found that at silica weight fraction of 0.79 (%w/w), the composite had optimum compressive strength, i.e. 70.5 MPa, or increased up to 22.4% of that without silica. The final compressive strength was very comparable to some building goods such as sandstones and bricks. The composite density was also measured and obtained that it was about 0.9 g/cm
Key Engineering Materials
In this paper, an analytical expression of the electron spin-dependent tunneling current through ... more In this paper, an analytical expression of the electron spin-dependent tunneling current through a potential barrier by applying a bias voltage was investigated. An Airy wavefunction was applied to derive the transmittance through the barrier by considering a zinc-blende material, which depends on the spin states indicated as ‘up’ and ‘down’. The obtained transmittance was employed to compute the polarization and spin-dependent tunneling current. The spin-dependent tunneling current was then observed at various bias voltages and temperatures. It was shown that the spin-polarized current increases as the bias voltage increases. It was also shown that the increase of temperature enhances the spin-dependent tunneling current.
Progress in Natural Science: Materials International
IOP Conference Series: Materials Science and Engineering
Nata de coco is a bacterial cellulose produced by Acetobacter xylinum in the process of fermentin... more Nata de coco is a bacterial cellulose produced by Acetobacter xylinum in the process of fermenting coconut water. It is renowned for its high fiber content. The chewiness of nata de coco is proportional to the fiber content. There are many brands of nata de coco available in the market. Six different brands are included in this study. The mechanical strengths have been evaluated using a Universal Testing Machine. Based on the tensile test results, the lowest Young's modulus is 3 MPa, attributed to the brand labeled as F as the most elastic nata de coco among the six brands. The degree of elasticity of nata de coco also corresponds to the sugar content. Further, the optical properties have been observed using a UV/Vis Spectrometer. Clearer nata de coco yields higher transmittance value. Meanwhile, the turbidity commensurate the nitrogen content.
IOP Conference Series: Materials Science and Engineering
We have successfully fabricated solar cell using flexible counter electrode of graphite powder. T... more We have successfully fabricated solar cell using flexible counter electrode of graphite powder. TiO 2 /graphite suspension was simply poured onto heated Fluorine Tin Oxide (FTO) substrate and kept heated at 200 o C for 2 hours. PVA.LiOH polymer electrolyte was employed as a positive charge transfer medium. The counter electrode was made of graphite powder which is manually deposited on transparent plastic using tube-shaped metal which its surface covered with tissue of 2 mm thick. Graphite powder was deposited by straight motion of 20 movements for one coating or one layer. The same activity was repeated on the stacked film to increase the conductivity of the film. Resistivity and transmittance measurement of the film was performed by four-point probe method and UV-Vis equipment respectively. The film thickness and 2-D porosity were measured using an electronic microscope and ImageJ software orderly. The film resistivity and transmittance gradually decreased with the increase of coating number and reached the resistivity of 0.35 Ω.cm and transmittance of 5% for 40 times of coating. At the same time, the film thickness was saturated at the 30 times coating and reached the thickness of 9.4 µm. The film 2-D porosity which indicated how well the surface of the film covered the graphite also decreased to reach the film porosity of 18%. The most conductive film (40 times coating) was used as a flexible counter electrode in TiO2/graphite solar cell. The efficiency of this structure was 0.4 %, a reasonable efficiency achievement for a cheap material and easy method used.