10x10 Cm2 Research Articles

Evaluation of AAA and XVMC Algorithms for Dose Calculation in Lung Equivalent Heterogeneity in Photon Fields: A Comparison of Calculated Results with Measurements.

The aims of the present work are (1) to evaluate dose calculation accuracy of two commonly used algorithms for 15 MV small photon fields in a medium encompassing heterogeneity and (2) to compare them with measured results obtained from gafchromic film EBT2. Authors employed kailwood (Pinus Wallichiana) to mimic lung. Briefly, seven Kailwood plates, each measuring 25x25 cm2 of varying thicknesses totaling 13 cm equivalent to the mean thickness of an adult human lung, were sandwiched between 5 cm tissue equivalent material from top and 10 cm below. Physical measurements were performed using Radiochromic film EBT2. The field sizes of 1x1, 2x2, 5x5 and 10x10 cm2 were selected at 100 cm SSD. Simulations were performed using EGSnrc/DOSRZnrc Monte Carlo code. The dose variation inside the inhomogeneity and near the interface was calculated using AAA & XVMC algorithm. Preliminary results show that there is large variation of dose inside inhomogeneity. The maximum variation of dose inside the inhomogeneity for 1x1 cm2 was found 40% by AAA and 4.5% by XVMC compared to measured/simulated results. For the field size of 2x2 cm2, these figures were 27% by AAA & 3.5% by XVMC. For 5x5 cm2 field size, the variation is small which becomes insignificant for larger fields. The results presented in this work indicate that for smaller fields, XVMC algorithm gives more realistic prediction, while there is the need for caution on using AAA algorithm for dose calculations involving small area irradiation encompassing heterogeneities and low-density media.

Comparison of absorbed dose distribution 10 MV photon beam on water phantom using Monte Carlo method and Analytical Anisotropic Algorithm

Treatment planning is a process of radiation therapy performed by medical physicists in the hospital. This process can be understood as a simulation to determine parameters such as photon energy, field size, and the absorbable dose to be received by the patient. Simulation treatment planning is usually done using TPS ECLIPSE with AAA or Acuros XB method that has been integrated into it. In this research, the comparison of the distribution of absorbent dose of 10 MV photon at water phantom using Monte Carlo-EGSnrc and AAA-ECLIPSE method was used. Monte Carlo simulations were performed with 6x6 cm2, 10x10 cm2, and 20x20 cm2 field size variations and initial electron energy variations 10.1 MeV, 10.2 MeV, 10.3 MeV and 10.4 MeV. The design and simulation of Linac heads are done using BEAMnrc and the calculation of absorbent doses in this water phantom using DOSXYZnrc. The BEAMnrc simulated particle information was analyzed using BEAMDP. To obtain the depth dose distribution or PDD and PROFILE the dose is done using statdose code. Based on the data processing, the result shows that the mean deviation of PDD and Dmax from the three field sizes is 7.09% for 10.1 MeV, 2.71% for 10.2 MeV, 2.86% for 10.3 MeV and 7.39% for 10.4 MeV. These results indicate that the initial electron energy has the least deviation of 10.2 MeV. As for the dose profile in the field size 10x10 cm2 obtained deviation 6.65% to 10.2 MeV

Contamination Measurements of Patient’s Lead-Insulated Rooms After I-131 and LU-177 PSMA Treatment via Sweeping Test

I-131 and Lu-177 PSMA radionuclides have been widely used in the field of nuclear medicine to treat thyroid cancer for many years. In this treatment, the patients whose dose rate measurements are less than 3 mR/h are generally discharged from the lead-insulated rooms where they are hospitalized. The aim of our study is to evaluate the contamination measurements of these rooms after I-131 and LU-177 PSMA treatment and to ensure radiation safety. A sweeping test was carried out by using Whatman papers (10x10 cm2 in size) to take samples from designated areas of these rooms in which three patients were treated with Lu-177 PSMA and four patients were treated with the I-131 radionuclide. Whatman papers are placed inside different tubes to prevent external contamination. Afterward, counting procedure was taken to the tubes for one minute by using the gamma counter which has different calibration factors both for Lu-177 and I-131 radionuclides. For the background extraction, one-minute counting test was applied to one of the Whatman papers that were not used for sweeping and background value was then obtained. It was statistically understood that the highest contamination rate was observed on the surface of toilet potteries in each room. As a result, ventilation of the room, meticulous cleaning of contaminated areas and the sweeping test must be implemented in each room where the patients are treated with radionuclides before the treatment of other patients.

The PSD CBM Supermodule Response Study for Hadrons in Momentum Range 2 – 6 GeV/c at CERN Test Beams

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Effect of Dust Deposition on the Performance of Thin Film Solar Cell

The effect of dust on the performances of the thin-film solar cell CZTS (Cu2ZnSnS4) was investigated. With the use of the spectrophotometric measuring instrument, an experimental study was made on one piece of glass of 10X10 cm2 with different levels of deposited dust (soil) , it will allow to estimate the resulting solar spectrum affected by the dust deposed on the piece of the glass, the affected spectrum by the dust deposition is used as an input spectrum for solar cell simulator SCAPS-1D (Solar Capacitance simulator in one dimension), the obtained results showed that when the accumulation of the dust increased on the solar cells surface, the short current density and the maximum power of the solar cells was affected strongly. DOI: http://dx.doi.org/10.5755/j01.eie.24.1.20158

Komunitas Makrozoobentos sebagai Indikator Biologis Kualitas Air Sungai Masang Kecil yang Menerima Limbah Cair Industri Minyak Kelapa Sawit di Kinali Pasaman Barat

The industrial liquid waste of crude palm oil contains organic material that can lead to degradation of water quality and ultimately affect the macrozoobenthos communities living on the river bed. The Masang Kecil River in Kinali Pasaman Barat receives the liquid waste of the palm oil industry. The research aimed to find out the composition and structure of macrozoobentos community in Masang Kecil River and determine the water quality of river based on macrozoobenthic community structure was done in June 2017. The research was conducted by survey method with purposive sampling technique. Samples were collected on 3 stations: Station I before entering the liquid waste of palm oil industry, Station II after entering the waste, Station III is located after Station II which has been entered by Anak Aia stream. In each station collected three samples of macrozoobentos with a surber net size of 30x30 cm2. The results showed that macrozoobenthos community found 43 species consist of 33 species of Insecta, Oligochaeta 4 species, Gastropoda 3 species, Hirudinae 2 species, Arachnida and Turbellaria one species respectively. The largest number of individuals was shown by Insecta (71.89%) followed by Hirudinea (25.1%) and the other class was not more than 3%. The highest density is found at station III and the lowest at station I. The dominant species on station I were Stenelmis sp. and Psephenoides sp., stations II and III were Erphobdella sp. and Hydropsyche elisoma. The diversity index ranges from 1.49 to 3.01. The index of equitability ranges from 0.47 to 0.89, the dominant index ranges from 0.06 to 0.43. The similarity of communities between station ranged from 38.46 - 55.0%. Based on the index of diversity, water quality in Station I was classified as not polluted, Station II and III classified as moderate.

Dynamics of dry spots in the liquid film moved by the gas flow in the mini-channel under intensive local heating

Experimental studies of hydrodynamics and the heat transfer crisis were carried out for a two-phase stratified flow in a mini-channel with intensive heating from a heat source of 1x1 cm2. It has been established that as the heat flow increases, the total area of dry spots on the heater increases, but when a certain temperature of the heater surface reaches ≈100 °C, the area of dry spots begins to decrease. With the help of high-speed visualization (shooting speed 100000 frames per second), several stages of formation of a dry spot (a typical size of the order of 100 microns) were isolated. It was found that at a heat flux of 450 W/cm2 about 1 million dry spots per 1 second are formed and washed on the surface of the heater (1 cm2). The speed of the contact line when dry spot is forming reaches 10 m/s.

Coating of molybdenum oxide on anodized aluminium plate applied for ultracapacitor electrodes

This research studied on the coating of molybdenum oxide on anodized aluminium plate via electrochemical plating technique applied for ultracapacitor electrodes. Preparation of the samples, aluminium plates with the size of 1X1 cm2 were anodized at voltage of 6, 12 and 24 volts with the constant electric current of 6 Amperes for 10, 20 and 30 minutes, respectively. The plate samples were then coated with molybdenum oxide by electrochemical plating technique. Thereafter, the samples were examined using the SEM techniques. Besides, the surface areas and the chemical composition of the plate samples were determined by AFM and XPS techniques, respectively. The results show that transitions metal oxide MoO3 can be obtained from MoO3/Al2O3 film prepared by electrochemical plating technique.

Comparison of Measurements in Small Fields from an MR-LINAC

To investigate beam profiles for small square fields from a 1.5 T MRI – 7 MV linear accelerator system (MR-Linac) measured with Gafchromic film, Fricke gel films, and a microDiamond detector. EBT-3 radiochromic films were irradiated to 4 Gy at isocenter distance at 5 cm depth inside a water phantom. 2x2, 3x3, 5x5, and 10x10 cm2 fields were delivered by an MR-Linac while the magnetic field (B-field) was turned off. Fricke-type gels were manufactured in-house, poured into 5-mm thick sheets and stored at 4⁰C for 24 hours prior to irradiation. The gel sheets were placed at isocenter at 5 cm depth in a solid water phantom and irradiated to 4Gy for each field size. All gels and films were scanned with an Epson 10000XL flatbed scanner pre- and post-irradiation. In-plane and cross-plane beam profiles were measured for all four field sizes with a PTW60019 microDiamond detector at 5 cm depth inside a water phantom under the same conditions. In-plane and cross-plane profiles measured with the planar detectors were analyzed and compared to profiles obtained with the microDiamond detector. All measurements were repeated with the B-field turned on. With the B-field off, in-plane and cross-plane profiles measured with film agreed to approximately 1% with microDiamond measurements. Compared to the microdiamond data, the 10x10 cm2 cross-plane profile from film measurements indicated slightly more than 1% higher signal more than 3 cm away from the central axis. The 80/20 penumbra regions overlapped for both detectors. The shape of the cross-plane profiles measured with gel dosimetry conformed with both film and microDiamond. The gel measurements exhibited more signal variations inside the radiation field and reported lower doses in the penumbra. With the B-field on, the effect of the magnetic field was clearly seen. In-plane profiles appeared symmetric while cross-plane profiles were noticably asymmetric. Film and microDiamond measurements agreed within 1-2% for all four fields. The shape of the profiles measured with gels agreed with both film and microDiamond. In regions of non-uniform thickness the gels demonstrated variations in signal. Both microDiamond and EBT-3 film offer a valuable means to measure small fields with steep dose gradients from the MR-Linac. Maintaining good quality control during the fabrication process of gel sheets is crucial to obtain uniform sheet thickness. Further investigation of gel sheets will be pursued as an alternative to film measurements.

Transparent Thin Film Lithium Ion Batteries

Novel multifunctional electronic devices (internet of things (IoT), wearables) do no longer require a conventional energy storage device, but a power source that can be perfectly integrated with the overall architecture of these devices, and ensure an additional structural function [1]. Within this context, transparency, amongst other functions, presents a particular challenge. Despite the potential advantages of integrating such energy storage with windows, screens, glasses and other optoelectronic devices, only a few studies reported on transparent lithium ion batteries [2,3]. In the present work, we report on the development of transparent all solid inorganic thin film lithium ion batteries (TFBs). Our transparent TFBs are realized considering a geometric engineering of battery materials and using advanced microfabrication techniques. The transparent TFBs are realized on 8’’ glass substrate and present a design with a grid structured active area consisting of LiCoO2/LiPON/Si based stack (Figure 1.a, 1.b). All materials are obtained by physical vapor deposition techniques. Specific photolithography and etching processes have been carried out to achieve structures below human eye resolution. transparent TFBs are microfabricated with varied architectures: several geometric designs corresponding to transmittances ranging between 25 and 60%, for each design different thicknesses related to active layers have been considered as well (up to 10µm and 0.1µm, respectively for LiCoO2 and Si based electrodes). UV-vis transmittance up to 60% have been measured for the obtained transparent TFBs (Figure 1.c). The 2x2 cm² transparent TFBs delivered discharge capacity as high as 0.5mAh upon galvanostatic cyling (at C/2 rate within 4.2-3V voltage range) for the 60% transmittance design. The capacity variation trend (Figure 1.d) shows a first phase (50 cycle) of a gradual decrease with an average capacity loss of 0.15% per cycle, and thereafter a second phase (50 cycles) with almost stable capacity. Particular attention is given to the effects of architecture parameters (geometric design, electrode thickness and cell balancing) on TFB optical and electrochemical properties. To the best of our knowledge, this work is the first demonstration of transparent all inorganic thin film lithium batteries. While reported studies are limited to battery structures involving liquid or polymer materials, our transparent TFBs may contribute to improve form factor freedom, extend operating temperature ranges and enhance long term stability, the whole being obtained by a fabrication process viable for industrial high volume production.

Volatile Organic Compound (VOC) Removal via Photocatalytic Oxidation Using TiO2 Coated Nanofilms

In this paper, toluene removal via photocatalytic oxidation using TiO2 dip coated nanofilms is presented. Nanofilms were synthesized from bacterial cellulose using the electrospinning technique. The physical properties of the nanofilms were analyzed by scanning electron microscopy (SEM). The ratio of bacterial cellulose/nylon used in the spinning process was 0.165:1. The results from SEM showed that the structure of the TiO2 composite nanofilms was rutile crystalline with an average particle size of 20 nm, and synthesized nanofilms had an average size of 20 - 30 nm. The band gap energies of TiO2-dip coated nanofilms ranged from 3.18 - 3.21 eV. SEM results of TiO2 coated nanofilms suggested that the TiO2 was rather uniformly distributed onto the surface of the nanofilms. The actual amount of TiO2 coated on the nanofilms was estimated using thermogravimetric analysis (TGA) for 1x1 cm2 surface area. It was found that 0.1852, 0.2897 and 0.7275 mg of TiO2 were coated on the surface of the nanofilms for 1, 2.5 and 5 % (weight) TiO2 dosage, respectively. The photocatalytic activity of the nanofilms was tested for the removal of gaseous toluene in a photocatalytic reactor. Experimental conditions were set as follows: UV light intensity of approximately 2.7 mW.cm-2, flow rate of 0.2 L.min-1, and an initial toluene concentration of about 200±20 ppm, and a retention time at 200 min. The degradation rate of toluene increased with increasing dosage of TiO2 from 1, 2.5 and 5 %. The nanofilms at a 5 % dosage yielded the highest removal efficiency of 92.71 %, followed by the 2.5 and 1 % dosage, respectively.

Design of Leakage Gas Induction Channels for Reliable Planar-Type Solid Oxide Fuel Cell Stacks

The leakage of gas in a planar solid oxide fuel cell (SOFC) stack is one of the important factors associated with stack degradation. When the fuel leaks to the air electrode, the catalytic property of the cathode deteriorates. Further, when air leaks to the anode comprised of Ni metal, the electrolyte thin film is peeled from the anode surface as result of the re-oxidation of Ni. Therefore, one of the ways to prevent these deterioration characteristics of the SOFC stack is to design a sealing method that can prevent gas leakage. In this study, we have developed a stack with specially designed channels which incorporates sealing gaskets that release leaked gas to outside, thereby preventing it from flowing into the fuel and air electrodes and ensuring the stability of the SOFC stack. The stack is designed to function with 10x10 cm2 size cells, and to undergo frequent thermal cycles rising from room temperature to operation temperature and then back to room temperature.

Preliminary investigation of the dosimetric properties of ClearView™ dosimeter

ClearView™ is a single-use radiochromic 3D dosimeter designed by Modus Medical Devices Inc. Some of the dosimetric characteristics of this gel, such as response as a function of dose and as a function of energy were investigated. Moreover, a 400 mL jar was irradiated with a 1x1 cm2 field and PDD and cross-profiles were compared to those obtained with active detectors. Small volumes of gels were found to exhibit a linear response to dose in the dose range 10-80 Gy. Promising PDD and cross profiles were obtained. Artefacts obtained in high resolution for the PDD are suspected to come from small inhomogeneities in the gel.

PNFLBA-14 EARLY IN VIVO DETECTION OF METASTATIC BLADDER CANCER IN MICE USING MOLECULAR MRI

You have accessJournal of UrologyPlenary: Next Frontier (PNFLBA)1 Apr 2017PNFLBA-14 EARLY IN VIVO DETECTION OF METASTATIC BLADDER CANCER IN MICE USING MOLECULAR MRI Joel Slaton, Nataliya Smith, Debra Saunders, Robert Hurst, and Rheal Towner Joel SlatonJoel Slaton More articles by this author , Nataliya SmithNataliya Smith More articles by this author , Debra SaundersDebra Saunders More articles by this author , Robert HurstRobert Hurst More articles by this author , and Rheal TownerRheal Towner More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.03.040AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Early detection of bladder cancer metastases might provide the potential for early treatment of metastatic disease. We previously reported on the use of a bladder tumor-binding peptide (BTBP)2 coupled to a Gd-DOTA MRI contrast agent (BTBP-probe)3 delivered intravesically to visualize bladder cancer growing on the bladder surface of an orthotopic mouse model, In this new report we demonstrated the use of this probe delivered intravenously to detect micrometastic spread of cancer to distant organs. METHODS MRI Studies: MRI experiments were done on a Bruker Biospec 7.0 Tesla/30 cm horizontal-bore imaging system. Multiple abdominal region 1H-MR image slices were taken using a RARE multislice (repetition time (TR) 1.3 s, echo time (TE) 9 ms, 256x256 matrix, 4 steps per acquisition, 3x3 cm2 field of view, 0.75 mm slice thickness). Mouse abdominal organs were imaged at 0 (pre-contrast) and at 3-4 hours post-contrast agent injection. Mice were injected intravenously with the BTBP-Gd-DOTA contrast agent (100μl/mouse; 50μmol/L). T1-weighted images were obtained using a variable TR (repetition time) spin-echo sequence (TR, 200-1600 ms; TE, 15 ms; NA, 2). Pixel-by-pixel relaxation maps were reconstructed from a series of T1-weighted images using a nonlinear two-parameter fitting procedure. The T1 value of a specified region-of-interest (ROI) was computed from all the pixels in the identified ROIs. MRI scans were obtained 6-7 weeks post-implantation of bladder tumors to identiy metastatic lesions. RESULTS Molecular MRI (mMRI) was used to detect the presence of the BTBP-probe via a substantial decrease in T1 relaxation, measured as T1 relaxation difference, within tumor regions of mice administered the BTBP-probe (p<0.05) compared to the controls. Both primary and metastatic tumors were detected. CONCLUSIONS We used mMRI to show for the first time non-invasive in vivo early detection of bladder tumor metastases in a mouse model for bladder carcinoma. Using mMRI with a bladder tumor-binding peptide targeted probe provides the advantage of in vivo image resolution and spatial differentiation of regional events in early detection of bladder cancer metastases. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e916 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Joel Slaton More articles by this author Nataliya Smith More articles by this author Debra Saunders More articles by this author Robert Hurst More articles by this author Rheal Towner More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Material processing of oil palm empty fruit bunches for use as raw material of conductive carbon paper

Empty fruit bunches of oil palm is a by-product of the palm oil industry that contains a high element of carbon. This by-product can be processed into a conductive carbon paper that could be applied as fuel cell electrodes. Carbon paper for this application must be conductive, porous, and hydrophobic. Utilization of oil palm empty fruit bunches begins with the carbonization process at a temperature of 500°C that produced charcoal. It is followed by heating at temperature of 900°C and 1300°C. To obtain the carbon paper, powdered charcoal with polymer binder (PEG and EVA) were mixed in solvent and molded using tape casting method. This process successfully produced carbon paper with dimensions of ±(20x20) cm2 and a thickness of 0.1-0.3 mm. Properties of carbon paper were characterized and analyzed in terms of electrical conductivity, porosity, hydrophobic property, and microstructure. Polytetrafluoroethylene (PTFE), a hydrophobic agent, was treated on carbon paper to enhance the hydrophobicity of the carbon paper. PTFE coating on the surface of the carbon paper could change their physical properties. Carbon paper shows excellent properties in terms of porosity and hydrophobicity. Whereas, its electrical property needs to be improved further by increasing the pyrolysis temperature. But overall, this might show a potential GDL material for PEMFC.

The angular dependence of a two dimensional monolithic detector array for dosimetry in small radiation fields

The purpose of this study is to investigate the directional dependence of a two dimensional monolithic detector array (M512) under 6 MV photon irradiation and to evaluate the effect of field size on angular dependence. Square fields of sizes: 3x3 cm2 and 10x10 cm2 were measured at the iso-centre of a cylindrical phantom. Beam angles with incidences from 00- 1800 in increments of 150 were used to investigate the central pixel angular response of M512, normalized to the pixel response for normal (0°) beam incidence. The angular response of the detector was compared to the response of EBT3 radiochromic film in the identical geometric orientation. The maximum angular dependence was observed at the angle 90°±15° to be -18.62% and -17.70% for the field sizes 3x3 cm2 and 10x10 cm2, respectively. The angular dependence of M512 showed no significant difference between field sizes of 3x3 cm2 and 10x10 cm2 (p>0.05). The maximum dose difference measured by the central pixel of M512 and EBT3 for all angles are -20% for 3x3 cm2 field size and -18.58% for the 10x10 cm2 field. The diode array’s size and packaging effects the angular response of the detector. The angular correction factor is necessary to apply to increase accuracy in dosimetry for arc treatment delivery.

Development of solution-based electrodes from nanocomposite material between PEDOT:PSS and ITO nanoparticles

Electrodes based on low-temperature preparation such as ink jet printing have been famously used in plastic electronic devices. The aim of this work is to investigate the specific properties of composite materials between nanoparticles of indium tin oxide (np-ITO) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) as an alternative electrode for plastic electronic devices. The composite materials were prepared as a function of np-ITO concentration varied from 1 to 20 w/v%. The 1x1 cm2 hybrid electrodes were fabricated by drop casting method on the microscope slide. This method offers many advantages, including simple preparation, low manufacturing cost and short fabricating time. The electrical resistance of the hybrid films was measured using two-probe measurement. Moreover, the surface morphology of the composited film was explored by optical microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results clearly suggest that mixing np-ITO with PEDOT:PSS can significantly improve conductivity of the composited system. Average value of electrical resistance measured from np-ITO, PEDOT:PSS and composite film are 87.58 kΩ, 40.33 kΩ and 393 Ω, respectively. The significant reduction of film resistance can be explained by the conducting paths made up by PEDOT:PSS to connect np-ITO domain.

Optimisation of output factor measurements using the Magic Plate 512 silicon dosimeter array in small megavoltage photon fields

We evaluate the impact of an air gap and optimization of this air gap for the MP512 silicon detector array when operated in dosimetry mode for small photon field measurements in solid water. We present output factor measurements for 6MV and 10 MV photon beams with the square field sizes ranging from 0.5 to 10 cm2. The size of the air gap above the MP512 detector was changed from 0.5, 1.0, 1.2, 2.0 and 2.6 mm. We compare the output factors measurements of the MP512 with EBT3 film and the MOSkin dosimeter. For the two photon energies investigated, we find that the output factor measured by the MP512 reduce with increasing air gap and reducing of field size. The reduction in output factor is most pronounced for the 0.5 and 1 cm2 field sizes. The air gap of 0.5 mm and 1.2 mm showed good agreement with the EBT3 film and MOSkin output factor for 6 and 10 MV photon fields, respectively. The negligible effect on dosimetry for the field sizes larger than 4x4 cm2 demonstrates that the electronic disequilibrium caused by small air gap only influences the dosimetry measurements for small fields. The study shows that the output factor reduction is enhanced by increasing of air gap and demonstrates that the optimal air gap for the MP512 at 6 and 10 MV photon fields is 0.5mm.

Electrochemical Characteristics of Large Area Thin Film Supercapacitors for Flexible Electronic Applications

Electronic products have been asked to be small, light, safe, eco-friendly and even flexible. Supercapacitors are one of the great candidates of the next generation rechargeable energy storage devices for the portable electronic devices. Here, we have proposed a new fabrication approach for making a large area thin film supercapacitor that achieved moderate areal capacitance and robust mechanical and thermal strength. The total thickness of a packaged device was ~0.3 mm. The fabricated devices had the electrode dimension of 10x10 cm2. They showed good mechanical flexibility with no change in the capacitance of the device after 1000 bending cycles with the bending radius of 20 mm and superior long-term thermal stability for for 2,000 hours at 60℃. It indicated that the unique film-type energy storage device for commercial small electronic applications has been developed.

DopLa Solar Cells with Texturized Front Surface

In this work, we report on improving efficiency of DopLa cells fabricated on p-type substrates. This type of solar cells has all the highly-doped regions based on laser doping from dielectric films resulting in a very simple fabrication process. Depending on the dopant type, emitter regions or high/low doping junctions related to base contacts can be created. The emitter regions are located at the rear surface in order to be contacted by a continuous metal film without penalizing in shadowing losses, while the front surface shows a typical finger grid configuration with the base contacts under the metal. In a previous work, the reported efficiency was limited by optical losses at the front planar surface. As a consequence, we focus on the introduction of a texturized front surface to the device. Firstly, we characterize the contact formation by laser processing on texturized surfaces by SEM image showing that the size of the contacted region is difficult to determine. By measuring contact resistance and surface recombination velocity, we deduce that the laser process of such surfaces leads to a contacted region which is smaller than the one where passivation is lost. The obtained information is included in 3D simulations to get the optimum size of the contacts, i.e. optimum laser power. Additionally, a new front grid metallization is introduced in order to reduce shadowing. Due to the rear emitter configuration of these devices, front surface recombination is crucial for collecting photogenerated carriers. Thus, optimum laser power is very close to the minimum to obtain a reliable contact. Finally, 2x2 cm2 solar cells are fabricated with a best efficiency of 17.0%.