Betavoltaic performance under extreme temperatures

Longevity of sensors and portable devices is severely limited by temperature, chemical instability, and electrolyte leakage issues associated with conventional electrochemical batteries. Betavoltaics, which operate similar to photo voltaics, can operate in a wide temperature range safely without permanent degradation. Though not a new concept, which began in the 1950's and peaked in the mid 1970's, research has been minimal and sporadic until recent advancements in ultra-low power electronics and materialization of low power applications. The technology is rapidly maturing, generating research, and development in increasing the beta emitting source and semiconductor efficiencies. This study presents an update on betavoltaic technology, results from temperature evaluation on commercially available General Licensed betavoltaic cells, development of a hybrid system for latent and burst power, modeling and simulation techniques and results, and current and proposed research and development. Betavoltaic performance was successfully demonstrated for a wide temperature range (-30?C to 70?C). Short circuit current and open circuit voltage were used to compare electrical performance. Results indicate that the open-circuit voltage and maximum power decreased as temperature increased due to increases in the semiconductor's intrinsic carrier concentration.

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Temperature Dependence of Commercially Available Betavoltaic Cells

Volume 5: Student Paper Competition ◽

10.1115/icone24-60304 ◽

2016 ◽

Author(s):

Darrell Cheu ◽

Thomas Adams ◽

Shripad Revankar

Keyword(s):

Open Circuit Voltage ◽

Short Circuit ◽

Short Circuit Current ◽

Photovoltaic Cell ◽

Open Circuit ◽

Maximum Power ◽

Electrical Performance ◽

Portable Devices ◽

Cold Environments ◽

Run Off

There is an increasing need for devices that can be powered for extended periods of time where it is difficult or impossible to maintain or replace, such as pacemakers, long term space flight or undisturbed sensors for military use. Presently, most portable devices run off a Lithium-Iodide battery, which gives a high amount of power but could only last approximately 2 to 5 years, requiring frequent replacement. However, replacement is unnecessary for betavoltaic cells as they can last at least 20 years. City Labs Inc. received a general license for commercially available tritium betavoltaic cells that were validated at extreme temperatures without permanent degradation. To fully determine the effectiveness of a betavoltaic cell, the electrical performance (I-V curves) of three betavoltaics were evaluated while temperatures were ramped up and down from −30°C to 70°C. Short circuit current, open circuit voltage, maximum power and fill factor were used to compare electrical performance. Results indicated that the open-circuit voltage and maximum power decreased as temperature increased, suggesting that betavoltaic cells are suited for cold environments below 0°C, such as during nightfall when a photovoltaic cell may not be used.

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SymmTop: A Symmetric Circuit Topology for Ultra Low Power Wide Temperature-Range Applications

2015 IEEE Computer Society Annual Symposium on VLSI ◽

10.1109/isvlsi.2015.105 ◽

2015 ◽

Author(s):

Elena K. Weinberg ◽

Mircea R. Stan

Keyword(s):

Low Power ◽

Wide Temperature Range ◽

Ultra Low Power ◽

Circuit Topology ◽

Temperature Range

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Online current-sensorless estimator for PV open circuit voltage and short circuit current

Solar Energy ◽

10.1016/j.solener.2020.11.004 ◽

2021 ◽

Vol 213 ◽

pp. 198-210

Author(s):

Ahsan Nadeem ◽

Hadeed Ahmed Sher ◽

Ali Faisal Murtaza ◽

Nisar Ahmed

Keyword(s):

Open Circuit Voltage ◽

Short Circuit ◽

Short Circuit Current ◽

Open Circuit ◽

Current Sensorless

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IMPROVING STABILITY OF CHLOROPHYLL AS NATURAL DYE FOR DYE-SENSITIZED SOLAR CELLS

Jurnal Teknologi ◽

10.11113/jt.v80.10258 ◽

2017 ◽

Vol 80 (1) ◽

Cited By ~ 1

Author(s):

Zainal Arifin ◽

Sudjito Soeparman ◽

Denny Widhiyanuriyawan ◽

Suyitno Suyitno ◽

Argatya Tara Setyaji

Keyword(s):

Current Density ◽

Open Circuit Voltage ◽

Short Circuit ◽

Dye Sensitized Solar Cells ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Natural Dyes ◽

Dye Sensitized ◽

Sensitized Solar Cells

Natural dyes have attracted much researcher’s attention due to their low-cost production, simple synthesis processes and high natural abundance. However the dye-sensitized solar cells (DSSCs) based natural dyes have higher tendency to degradation. This article reports on the enhancement of performance and stability of dye-sensitized solar cells (DSSCs) using natural dyes. The natural dyes were extracted from papaya leaves by ethanol solvent at a temperature of 50 °C. Then the extracted dyes were isolated and modified into Mg-chlorophyll using column chromatography. Mg-chlorophyll was then synthesized into Fe-chlorophyll to improve stability. The natural dyes were characterized using ultraviolet-visible spectrometry, Fourier transform infrared spectroscopy, and cyclic voltammetry. The performance of DSSCs was tested using a solar simulator. The results showed the open-circuit voltage, the short-circuit current density, and the efficiency of the extracted papaya leaves-based DSSCs to be 325 mV, 0.36 mA/cm2, and 0.07%, respectively. Furthermore, the DSSCs with purified chlorophyll provide high open-circuit voltage of 425 mV and short-circuit current density of 0.45 mA/cm2. The use of Fe-chlorophyll for sensitizing the DSSCs increases the efficiency up to 2.5 times and the stability up to two times. The DSSCs with Fe-chlorophyll dyes provide open-circuit voltage, short-circuit current density, and efficiency of 500 mV, 0.62 mA/cm2, and 0.16%, respectively. Further studies to improve the current density and stability of natural dye-based DSSCs along with an improvement in the anchor between dyes and semiconducting layers are required.

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Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.171 ◽

2018 ◽

Vol 9 ◽

pp. 1802-1808 ◽

Cited By ~ 6

Author(s):

Katherine Atamanuk ◽

Justin Luria ◽

Bryan D Huey

Keyword(s):

Solar Cells ◽

Open Circuit Voltage ◽

Short Circuit ◽

Photovoltaic Performance ◽

Three Dimensional ◽

Short Circuit Current ◽

Open Circuit ◽

Photovoltaic Properties ◽

Order Of Magnitude ◽

Individual Grains

The nanoscale optoelectronic properties of materials can be especially important for polycrystalline photovoltaics including many sensor and solar cell designs. For thin film solar cells such as CdTe, the open-circuit voltage and short-circuit current are especially critical performance indicators, often varying between and even within individual grains. A new method for directly mapping the open-circuit voltage leverages photo-conducting AFM, along with an additional proportional-integral-derivative feedback loop configured to maintain open-circuit conditions while scanning. Alternating with short-circuit current mapping efficiently provides complementary insight into the highly microstructurally sensitive local and ensemble photovoltaic performance. Furthermore, direct open-circuit voltage mapping is compatible with tomographic AFM, which additionally leverages gradual nanoscale milling by the AFM probe essentially for serial sectioning. The two-dimensional and three-dimensional results for CdTe solar cells during in situ illumination reveal local to mesoscale contributions to PV performance based on the order of magnitude variations in photovoltaic properties with distinct grains, at grain boundaries, and for sub-granular planar defects.

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Prediction of Solar Irradiance Based on Artificial Neural Networks

Inventions ◽

10.3390/inventions4030045 ◽

2019 ◽

Vol 4 (3) ◽

pp. 45 ◽

Cited By ~ 4

Author(s):

Waleed I. Hameed ◽

Baha A. Sawadi ◽

Safa J. Al-Kamil ◽

Mohammed S. Al-Radhi ◽

Yasir I. A. Al-Yasir ◽

...

Keyword(s):

Neural Networks ◽

Artificial Neural Networks ◽

Solar Irradiance ◽

Open Circuit Voltage ◽

Low Cost ◽

Short Circuit ◽

Short Circuit Current ◽

Open Circuit ◽

Pv Module ◽

Artificial Neural

Prediction of solar irradiance plays an essential role in many energy systems. The objective of this paper is to present a low-cost solar irradiance meter based on artificial neural networks (ANN). A photovoltaic (PV) mathematical model of 50 watts and 36 cells was used to extract the short-circuit current and the open-circuit voltage of the PV module. The obtained data was used to train the ANN to predict solar irradiance for horizontal surfaces. The strategy was to measure the open-circuit voltage and the short-circuit current of the PV module and then feed it to the ANN as inputs to get the irradiance. The experimental and simulation results showed that the proposed method could be utilized to achieve the value of solar irradiance with acceptable approximation. As a result, this method presents a low-cost instrument that can be used instead of an expensive pyranometer.

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Effective Light Harvesting of Tandem Polymer Solar Cell

Journal of Solar Energy Engineering ◽

10.1115/1.4001150 ◽

2010 ◽

Vol 132 (2) ◽

Cited By ~ 5

Author(s):

Yi-Chun Chen ◽

Chao-Ying Yu ◽

Chih-Ping Chen ◽

Shu-Hua Chan ◽

Ching Ting

Keyword(s):

Solar Cell ◽

Molecular Orbital ◽

Open Circuit Voltage ◽

Polymer Solar Cell ◽

Short Circuit ◽

Active Material ◽

Weight Ratio ◽

Acid Methyl Ester ◽

Open Circuit ◽

Ito Glass

A novel soluble conjugated polymers, P2, with coplanar thiophene-phenylene-thiophene unit is designed and synthesized as suitable active material used in tandem cells to compensate the poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl-C71 butyric acid methyl ester (PC71BM) bulk-heterojunction cell in this paper. P2 polymer bears advantages in both low optical bandgap (1.7 eV) and high hole mobility properties (3.4×10−3 cm2/V-s from field-effect transistor measurement). Furthermore, the electrochemical studies of P2 indicate desirable highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO) band structure that enables a high open circuit voltage when pairing with PCBM acceptor. The best power conversion efficiency of this polymer solar cell thus far based on P2/PC71BM system with a weight ratio of 1:3 reached 4.4% with a short circuit current density (Jsc) of 10.2 mA/cm2, an open circuit voltage (Voc) of 0.81 V, and a fill factor (FF) of 0.53 under air mass (AM) 1.5 G (100 mW/cm2). The preliminary data of the tandem cell with indium tin oxide (ITO) glass/PEDOT:PSS/P2:PC71BM/TiOx/PEDOT:PSS/P3HT:PC71BM/TiOx/Al configuration has reached Jsc of 6.2 mA/cm2, Voc of 1.33 V, FF of 0.56 and an overall efficiency of 4.6% under AM 1.5 G (100 mW/cm2).

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Inkjet Printing Technology for Dye-Sensitized Solar Cells

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.1767 ◽

2012 ◽

Vol 476-478 ◽

pp. 1767-1770

Author(s):

Yu Li Lin ◽

Cheng Yi Hsu ◽

Chang Lun Tai

Keyword(s):

Open Circuit Voltage ◽

Short Circuit ◽

Dye Sensitized Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Dye Sensitized ◽

Tio2 Particles ◽

Ito Glass ◽

Sensitized Solar Cells ◽

Pet Substrate

The task of this study is to prepare the TiO2 film electrode for dye-sensitized solar cells (DSSC) on ITO PET substrate using a general jet-printer. The results were compared with that obtained using ITO glass substrate. In this study, the dispersion of TiO2 slurry was manipulated by changing the pH value of the solution to avoid agglomeration of TiO2 particles. The average TiO2 particles used in this study were measured about 130nm. The experimental results show that it has the best performance when the thickness of the TiO2 film was about 10μm. In ITO glass substrate, the measured short circuit current was about 5.03mA, the open circuit voltage was measured to be 0.65V. In ITO-PET substrate, the measured short circuit current was about 2.73mA, the open circuit voltage was measured to be 0.68V.

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