Euis Sustini | Institut Teknologi Bandung (original) (raw)
Papers by Euis Sustini
Journal of King Saud University - Science
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
AIP Conference Proceedings, 2010
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
IOP Conference Series: Materials Science and Engineering
Journal of King Saud University - Science
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
AIP Conference Proceedings, 2010
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
IOP Conference Series: Materials Science and Engineering