scholarly journals Modelling a Segmented Skutterudite-Based Thermoelectric Generator to Achieve Maximum Conversion Efficiency

2020 ◽  
Vol 10 (1) ◽  
pp. 408
Author(s):  
Aminu Yusuf ◽  
Sedat Ballikaya
Keyword(s):  
Temperature Gradient ◽  
Conversion Efficiency ◽  
Thermoelectric Generator ◽  
Mass Scale ◽  
Open Circuit ◽  
Scale Production ◽  
Compatibility Factor ◽  
Output Characteristics ◽  
Te Material ◽  
P Type

Thermoelectric generator (TEG) modules generally have a low conversion efficiency. Among the reasons for the lower conversion efficiency is thermoelectric (TE) material mismatch. Hence, it is imperative to carefully select the TE material and optimize the design before any mass-scale production of the modules. Here, with the help of Comsol-Multiphysics (5.3) software, TE materials were carefully selected and the design was optimized to achieve a higher conversion efficiency. An initial module simulation (32 couples) of unsegmented skutterudite Ba0.1Yb0.2Fe0.1Co3.9Sb12 (n-type) and Ce0.5Yb0.5Fe3.25Co0.75Sb12 (p-type) TE materials was carried out. At the temperature gradient T∆ = 500 K, a maximum simulated conversion efficiency of 9.2% and a calculated efficiency of 10% were obtained. In optimization via segmentation, the selection of TE materials, considering compatibility factor (s) and ZT, was carefully done. On the cold side, Bi2Te3 (n-type) and Sb2Te3 (p-type) TE materials were added as part of the segmentation, and at the same temperature gradient, an open circuit voltage of 6.2 V matched a load output power of 45 W, and a maximum simulated conversion efficiency of 15.7% and a calculated efficiency of 17.2% were achieved. A significant increase in the output characteristics of the module shows that the segmentation is effective. The TEG shows promising output characteristics.

Deposition of P-Type Nanocrystalline Silicon Using High Pressure in a VHF-PECVD Single Chamber System

2011 ◽  
Vol 1321 ◽  
Author(s):  
Xiaodan Zhang ◽  
Guanghong Wang ◽  
Xinxia Zheng ◽  
Shengzhi Xu ◽  
Changchun Wei ◽  
...  
Keyword(s):  
High Pressure ◽  
Solar Cells ◽  
Solar Cell ◽  
Conversion Efficiency ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Nanocrystalline Silicon ◽  
Open Circuit ◽  
Single Chamber ◽  
P Type

ABSTRACTIn this article, we present a study of boron-doped hydrogenated nanocrystalline silicon (nc-Si: H) films by very high frequency-plasma enhanced chemical vapor deposition (VHF-PECVD) using high deposition pressure. Electrical, structural and optical properties of the films were investigated. Dark conductivity as high as 2.75S/cm of p-type nc-Si: H prepared at 2.5Torr pressure has been achieved at a deposition rate of 1.75Å/s for 25nm thin film. By controlling boron and phosphorus contamination, single junction nc-Si: H solar cells incorporated p-layers prepared under high pressure and low pressure, respectively, were deposited. It has been proven that nanocrystalline silicon solar cells with incorporation of p layer prepared at high pressure has resulted in enhanced open circuit voltage, short circuit current density and subsequently high conversion efficiency. Through the optimization of the bottom solar cell and application of ZnO/Al back reflector, 10.59% initial conversion efficiency of micromorph tandem solar cell (1.027cm2) with an open circuit voltage of 1.3864V, has been fabricated, where the bottom solar cell using a high pressure p layer was deposited in a single chamber.

PHOTOELECTRICAL PROPERTIES OF p-TYPE AND n-TYPE ELECTRICAL CONDUCTIVITY AMORPHOUS CARBON THIN FILMS FOR APPLICATION IN ECONOMICAL CARBON-BASED SOLAR CELLS

2005 ◽  
Vol 12 (03) ◽  
pp. 343-350 ◽  
Author(s):  
M. RUSOP ◽  
T. SOGA ◽  
T. JIMBO
Keyword(s):  
Energy Conversion ◽  
Conversion Efficiency ◽  
Fill Factor ◽  
Short Circuit ◽  
Wavelength Region ◽  
Short Circuit Current ◽  
Energy Conversion Efficiency ◽  
Open Circuit ◽  
Photon Absorption ◽  
P Type

The successful deposition of boron ( B )-doped p-type ( p-C:B ) and phosphorous ( P )-doped n-type ( n-C:P ) carbon ( C ) films, and fabrication of p-C:B on silicon ( Si ) substrate ( p-C:B/n-Si ) and n-C:P/p-Si cells by the technique of pulsed laser deposition (PLD) using graphite target is reported. The cells' performances are represented in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm2, 25°C). The open circuit voltage (V oc ) and short circuit current density (J sc ) for p-C:B/n-Si are observed to vary from 230–250 mV and 1.5–2.2 mA/cm2, respectively, and to vary from 215–265 mV and 7.5–10.5 mA/cm2, respectively, for n-C:P/p-Si cells. The p-C:B/n-Si cell fabricated using the target with the amount of B by 3 Bwt% shows highest energy conversion efficiency, η = 0.20%, and fill factor, FF = 45%, while, the n-C:P/p-Si cell with the amount of P by 7 Pwt% shows highest energy conversion efficiency, η = 1.14%, and fill factor, FF = 41%. The quantum efficiencies (QE) of the p-C:B/n-Si and n-C:P/p-Si cells are observed to improve with Bwt% and Pwt%, respectively. The contributions of QE are suggested to be due to photon absorption by carbon layer in the lower wavelength region (below 750 nm) and Si substrates in the higher wavelength region. The dependence of B and P content on the electrical and optical properties of the deposited films, and the photovoltaic characteristics of the respective p-C:B/n-Si and n-C:P/p-Si heterojunction photovoltaic cells, are discussed.

Bi-Sb-Te Based Thin Film Thermoelectric Generator

2012 ◽  
Vol 538-541 ◽  
pp. 60-63 ◽  
Author(s):  
Zhao Kun Cai ◽  
Ping Fan ◽  
Zhuang Hao Zheng ◽  
Xing Min Cai ◽  
Dong Ping Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Seebeck Coefficient ◽  
Output Power ◽  
Power Factor ◽  
Thermoelectric Generator ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Thermoelectric Thin Films ◽  
P Type

N-type Bi2Te3 and p-type Sb2Te3 thermoelectric thin films have been prepared by RF and DC co-sputtering. The Seebeck coefficient of n-type Bi2Te3 and p-type Sb2Te3 thin films is about -122 μVK-1 and 108 μVK-1, the power factor is about 0.82×10-3 Wm-1K-2 and 1.60×10-3 Wm-1K-2. Then, the films have been selected to fabricate the thin film thermoelectric generator. The results show that the open-circuit voltage of 12.2 mV and the output power of 3.32 μW are obtained for a thin film generator with the temperature difference at 60 K.

scholarly journals Early fever detection on COVID-19 infection using thermoelectric module generators

2021 ◽  
Vol 11 (5) ◽  
pp. 3828
Author(s):  
Daniel Sanin-Villa ◽  
Oscar D. Monsalve-Cifuentes ◽  
Jorge Sierra Del Rio
Keyword(s):  
Thermoelectric Generator ◽  
Open Circuit Voltage ◽  
Numerical Study ◽  
Electrical Power ◽  
Thermoelectric Module ◽  
Open Circuit ◽  
Human Interaction ◽  
Hexahedral Mesh ◽  
Maximum Value ◽  
P Type

In 2020 the COVID-19 pandemic has suddenly stopped society and changed human interaction. In this work, a thermoelectric generator wearable device for early fever detection symptoms is presented as a possible solution to avoid higher propagation of this disease. To identify a possible fever symptom, numerical and parametric simulations are developed using a highquality-refined hexahedral mesh. At first, a 2-pair-leg thermoelectric module has undergone simulations to establish temperature conditions, open-circuit voltage, and power output generation; and secondly, these previous results are extrapolated for a larger thermoelectric module containing 28 pair-leg of N-P type material. The numerical study shows that a maximum value of electrical power of 60.70 mW was reached for 28-pair-leg N-P type thermocouples under a constant temperature difference of 20 K.

Using the Compatibility Factor to Design High Efficiency Segmented Thermoelectric Generators

2003 ◽  
Vol 793 ◽  
Author(s):  
G. Jeffrey Snyder ◽  
T. Caillat
Keyword(s):  
Conversion Efficiency ◽  
Refractory Metal ◽  
High Efficiency ◽  
Type Material ◽  
Thermoelectric Generators ◽  
Filled Skutterudite ◽  
Modest Increase ◽  
Compatibility Factor ◽  
P Type

ABSTRACTUsing thermoelectric compatibility, efficient thermoelectric generators are rationally designed. With examples, compatible and incompatible systems are explained and materials proposed for targeted development. The compatibility factor explains why segmentation of TAGS with SnTe or PbTe produces little extra power, while filled skutterudite increases the efficiency from 10.5% to 13.6%. High efficiency generators are designed with compatible n-type La2Te3, and similar p-type material, while incompatible SiGe alloys actually reduce the efficiency. A refractory metal with high p-type thermopower (> 100 μV/K) is required for development. The Chevrel compound Cu4Mo6Se8 is a compatible p-type metal that provides a modest increase in efficiency. A fully segmented generator using Bi2Te3-type, PbTe, TAGS, Zn4Sb3, skutterudite, La2Te3, and Chevrel compounds between 25° C and 1000° C will achieve 18.1% conversion efficiency.

Enhanced efficacy of defect passivation and charge extraction for efficient perovskite photovoltaics with a small open circuit voltage loss

2019 ◽  
Vol 7 (15) ◽  
pp. 9025-9033 ◽  
Author(s):  
Jin-Feng Liao ◽  
Wu-Qiang Wu ◽  
Jun-Xing Zhong ◽  
Yong Jiang ◽  
Lianzhou Wang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Open Circuit Voltage ◽  
Power Conversion ◽  
Charge Recombination ◽  
Open Circuit ◽  
Polymeric Semiconductor ◽  
Voltage Loss ◽  
Defect Passivation

A multifunctional 2D polymeric semiconductor was incorporated to provide surprisingly robust efficacy in grain boundary functionalization and defect passivation of perovskite, which suppresses charge recombination and thus affording an illustrious photovoltage of 1.16 V and power conversion efficiency of 21.1%.

scholarly journals Transparent All-Oxide Hybrid NiO:N/TiO2 Heterostructure for Optoelectronic Applications

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 988
Author(s):  
Chrysa Aivalioti ◽  
Alexandros Papadakis ◽  
Emmanouil Manidakis ◽  
Maria Kayambaki ◽  
Maria Androulidaki ◽  
...  
Keyword(s):  
Band Gap ◽  
Single Phase ◽  
Structural Disorder ◽  
Energy Band Gap ◽  
Nitrogen Doped ◽  
Nio Thin Film ◽  
Direct Band ◽  
Output Characteristics ◽  
Indirect Band Gap ◽  
P Type

Nickel oxide (NiO) is a p-type oxide and nitrogen is one of the dopants used for modifying its properties. Until now, nitrogen-doped NiO has shown inferior optical and electrical properties than those of pure NiO. In this work, we present nitrogen-doped NiO (NiO:N) thin films with enhanced properties compared to those of the undoped NiO thin film. The NiO:N films were grown at room temperature by sputtering using a plasma containing 50% Ar and 50% (O2 + N2) gases. The undoped NiO film was oxygen-rich, single-phase cubic NiO, having a transmittance of less than 20%. Upon doping with nitrogen, the films became more transparent (around 65%), had a wide direct band gap (up to 3.67 eV) and showed clear evidence of indirect band gap, 2.50–2.72 eV, depending on %(O2-N2) in plasma. The changes in the properties of the films such as structural disorder, energy band gap, Urbach states and resistivity were correlated with the incorporation of nitrogen in their structure. The optimum NiO:N film was used to form a diode with spin-coated, mesoporous on top of a compact, TiO2 film. The hybrid NiO:N/TiO2 heterojunction was transparent showing good output characteristics, as deduced using both I-V and Cheung’s methods, which were further improved upon thermal treatment. Transparent NiO:N films can be realized for all-oxide flexible optoelectronic devices.

scholarly journals Thermoelectric Properties of Carbon Nanotubes

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4561 ◽  
Author(s):  
Nguyen T. Hung ◽  
Ahmad R. T. Nugraha ◽  
Riichiro Saito
Keyword(s):  
Carbon Nanotubes ◽  
Figure Of Merit ◽  
Waste Heat ◽  
Quantum Confinement Effect ◽  
Electrical Energy ◽  
High Seebeck Coefficient ◽  
Te Material ◽  
P Type ◽  
State Device ◽  
Solid State Device

Thermoelectric (TE) material is a class of materials that can convert heat to electrical energy directly in a solid-state-device without any moving parts and that is environmentally friendly. The study and development of TE materials have grown quickly in the past decade. However, their development goes slowly by the lack of cheap TE materials with high Seebeck coefficient and good electrical conductivity. Carbon nanotubes (CNTs) are particularly attractive as TE materials because of at least three reasons: (1) CNTs possess various band gaps depending on their structure, (2) CNTs represent unique one-dimensional carbon materials which naturally satisfies the conditions of quantum confinement effect to enhance the TE efficiency and (3) CNTs provide us with a platform for developing lightweight and flexible TE devices due to their mechanical properties. The TE power factor is reported to reach 700–1000 W / m K 2 for both p-type and n-type CNTs when purified to contain only doped semiconducting CNT species. Therefore, CNTs are promising for a variety of TE applications in which the heat source is unlimited, such as waste heat or solar heat although their figure of merit Z T is still modest (0.05 at 300 K). In this paper, we review in detail from the basic concept of TE field to the fundamental TE properties of CNTs, as well as their applications. Furthermore, the strategies are discussed to improve the TE properties of CNTs. Finally, we give our perspectives on the tremendous potential of CNTs-based TE materials and composites.

Performance analysis of a lever piezoelectric energy harvester for roadway applications

2021 ◽  
pp. 1045389X2110014
Author(s):  
Guangya Ding ◽  
Hongjun Luo ◽  
Jun Wang ◽  
Guohui Yuan
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Open Circuit ◽  
Traffic Load ◽  
Energy Harvesters ◽  
Speed Sensor ◽  
Piezoelectric Energy ◽  
Optimal Load ◽  
Self Powered ◽  
Output Characteristics

A novel lever piezoelectric energy harvester (LPEH) was designed for installation in an actual roadway for energy harvesting. The model incorporates a lever module that amplifies the applied traffic load and transmits it to the piezoelectric ceramic. To observe the piezoelectric growth benefits of the optimized LPEH structure, the output characteristics and durability of two energy harvesters, the LPEH and a piezoelectric energy harvester (PEH) without a lever, were measured and compared by carrying out piezoelectric performance tests and traffic model experiments. Under the same loading condition, the open circuit voltages of the LPEH and PEH were 20.6 and 11.7 V, respectively, which represents a 76% voltage increase for the LPEH compared to the PEH. The output power of the LPEH was 21.51 mW at the optimal load, which was three times higher than that of the PEH (7.45 mW). The output power was linearly dependent on frequency and load, implying the potential application of the module as a self-powered speed sensor. When tested during 300,000 loading cycles, the LPEH still exhibited stable structural performance and durability.

scholarly journals Effect of Core-Shell Ag@TiO2Volume Ratio on Characteristics of TiO2-Based DSSCs

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ho Chang ◽  
Chih-Hao Chen ◽  
Mu-Jung Kao ◽  
Hsin-Han Hsiao
Keyword(s):  
Conversion Efficiency ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Open Circuit ◽  
Photoelectric Conversion Efficiency ◽  
Core Shell ◽  
Photoelectric Conversion ◽  
Shell Type ◽  
Degussa P25 ◽  
Triton X

This paper aims to develop photoanode material required by dye-sensitized solar cells. The material prepared is in the form of Ag@TiO2core-shell-type nanocomposites. This material is used to replace the titanium oxide powder commonly used in general DSSCs. The prepared Ag@TiO2core-shell-type nanocomposites are mixed with Degussa P25 TiO2in different proportions. Triton X-100 is added and polyethylene glycol (PEG) at 20 wt% is used as a polymer additive. This study tests the particle size and material properties of Ag@TiO2core-shell-type nanocomposites and measures the photoelectric conversion efficiency and IPCE of DSSCs. Experimental results show that the DSSC prepared by Ag@TiO2core-shell-type nanocomposites can achieve a photoelectric conversion efficiency of 3.67%. When Ag@TiO2core-shell-type nanocomposites are mixed with P25 nanoparticles in specific proportions, and when the thickness of the photoelectrode thin film is 28 μm, the photoelectric conversion efficiency can reach 6.06%, with a fill factor of 0.52, open-circuit voltage of 0.64V, and short-circuit density of 18.22 mAcm−2. Compared to the DSSC prepared by P25 TiO2only, the photoelectric conversion efficiency can be raised by 38% under the proposed approach.

Sign in / Sign up

Export Citation Format

Share Document