scholarly journals Performance Enhancement of an a-Si:H/μc-Si:H Heterojunction p-i-n Solar Cell by Tuning the Device Parameters

2021 ◽  
Vol 69 (2) ◽  
pp. 88-95
Author(s):  
Md Nazmul Islam ◽  
Himangshu Ranjan Ghosh
Keyword(s):  
Solar Cell ◽  
Fill Factor ◽  
Performance Enhancement ◽  
Low Frequency ◽  
Ultra Violet ◽  
Design Parameters ◽  
Microcrystalline Silicon ◽  
Donor And Acceptor ◽  
Hydrogenated Amorphous ◽  
Very High

In this work, the solar cell design parameters like- layer thickness, bandgap, donor and acceptor concentrations are varied to find optimum structure of a hydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon (μc-Si:H) heterojunction p-i-n solar cell. A thin a-Si:H p-layer of 1 to 5 nm followed by a thick a-Si:H i-layer of thickness 1400 to 1600 nm and then thin n-layer of thickness 1 to 5 nm with acceptor concentration of 102 cm−3 and donor concentration of 1020 cm−3 and the bandgaps of p-, i-, and n- layers with higher bandgaps closer to 2.2 eV for a-Si:H p-layer, 1.85 eV for a-Si:H i-layer, and 1.2 eV for μc-Si:H n-layer have showed better performances. The optimum cell has a JSC of 18.93 mA/cm2, VOC of 1095 mV, Fill factor of 0.7124, and efficiency of 14.77%. The overall external quantum efficiency of the numerically designed cell also remained very high from 85-95 % for wavelengths of 300-650 nm range. This indicates that the device will perform its best under both high and low frequency i.e. ultra-violet, near visible and visible light wavelengths. Dhaka Univ. J. Sci. 69(2): 88-95, 2021 (July)

Development of Stable a-Si/a-SiGe Tandem Solar Cell Submodules Deposited by a Very High Hydrogen Dilution at Low Temperature

1998 ◽  
Vol 507 ◽  
Author(s):  
Masaki Shima ◽  
Masao Isomura ◽  
Eiji Maruyama ◽  
Shingo Okamoto ◽  
Hisao Haku ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Silicon Germanium ◽  
Structural Variations ◽  
High Hydrogen ◽  
Hydrogen Dilution ◽  
Hydrogen Radicals ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous ◽  
Very High

ABSTRACTThe world's highest stabilized efficiency of 9.5% (light-soaked and measured by the Japan Quality Assurance Organization (JQA)) for an a-Si/a-SiGe superstrate-type solar cell submodule (area: 1200 cm2) has been achieved. This value was obtained by investigating the effects of very-high hydrogen dilution of up to 54:1 (= H2: SiH4) on hydrogenated amorphous silicon germanium (a-SiGe:H) deposition at a low substrate temperature (Ts). It was found that deterioration of the film properties of a-SiGe:H when Ts decreases under low hydrogen dilution conditions can be suppressed by the high hydrogen dilution. This finding probably indicates that the energy provided by hydrogen radicals substitutes for the lost energy caused by the decrease in Ts and that sufficient surface reactions can occur. In addition, results from an estimation of the hydrogen and germanium contents of a-SiGe:H suggest the occurrence of some kinds of structural variations by the high hydrogen dilution. A guideline for optimization of a-SiGe:H films for solar cells can be presented on the basis of the experimental results. The possibility of a-SiGe:H as a narrow gap material for a-Si stacked solar cells in contrast with microcrystalline silicon (μ c-Si:H) will also be discussed from various standpoints. At present, a-SiGe:H is considered to have an advantage over μ1 c-Si:H.

scholarly journals Performance Enhancement of a Multiresonant Piezoelectric Energy Harvester for Low Frequency Vibrations

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2770 ◽  
Author(s):  
Iman Izadgoshasb ◽  
Yee Lim ◽  
Ricardo Vasquez Padilla ◽  
Mohammadreza Sedighi ◽  
Jeremy Novak
Keyword(s):  
Cantilever Beam ◽  
Performance Enhancement ◽  
Low Frequency ◽  
Design Parameters ◽  
Vibration Source ◽  
Element Analysis ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Low Frequency Vibration ◽  
External Power Source

Harvesting electricity from low frequency vibration sources such as human motions using piezoelectric energy harvesters (PEH) is attracting the attention of many researchers in recent years. The energy harvested can potentially power portable electronic devices as well as some medical devices without the need of an external power source. For this purpose, the piezoelectric patch is often mechanically attached to a cantilever beam, such that the resonance frequency is predominantly governed by the cantilever beam. To increase the power generated from vibration sources with varying frequency, a multiresonant PEH (MRPEH) is often used. In this study, an attempt is made to enhance the performance of MRPEH with the use of a cantilever beam of optimised shape, i.e., a cantilever beam with two triangular branches. The performance is further enhanced through optimising the design of the proposed MRPEH to suit the frequency range of the targeted vibration source. A series of parametric studies were first carried out using finite-element analysis to provide in-depth understanding of the effect of each design parameters on the power output at a low frequency vibration. Selected outcomes were then experimentally verified. An optimised design was finally proposed. The results demonstrate that, with the use of a properly designed MRPEH, broadband energy harvesting is achievable and the efficiency of the PEH system can be significantly increased.

Structural and Optical Properties of a-Si:H/μc-Si:H:B Junctions in the a-Si:H-Based n-i-P Solar Cell Configuration

1997 ◽  
Vol 467 ◽  
Author(s):  
Joohyun Kohi ◽  
H. Fujiwara ◽  
C. R. Wronski ◽  
R. W. Collins
Keyword(s):  
Optical Properties ◽  
Solar Cell ◽  
Single Phase ◽  
Cell Structure ◽  
Chemical Vapor ◽  
Average Crystallite Size ◽  
Microcrystalline Silicon ◽  
Solar Cell Structure ◽  
P Type ◽  
Hydrogenated Amorphous

ABSTRACTWe have extended previous real time spectroscopie ellipsometry (RTSE) capabilities in order to investigate the effects of H2-plasma treatment of i-type hydrogenated amorphous silicon (a-Si:H) on the deposition of the overlying p-type microcrystalline silicon (μc-Si:H:B)) in the formation of an n-i-p solar cell structure. In this study, we compare in detail the nucleation and growth of p-layers by plasma-enhanced chemical vapor deposition (PECVD) from SiH4 highly diluted in H2 on the surfaces of untreated and H2-plasma treated a-Si:H i-layers. We find that for intended single-phase μc-Si:H:B p-layer PECVD under optimum conditions on an untreated i-layer surface, a wide gap (∼2.0 eV Taue gap) amorphous layer nucleates and grows in the first ∼150 Å. This layer develops uniformly to a bulk thickness of ∼150 Å, but gradually acquires a crystalline structure for thicknesses greater than the desired p-layer thickness (200 Å). In contrast, for p-layer PECVD under identical conditions on the H2-plasma treated i-layer, high-density crystalline nuclei form immediately. This conclusion is drawn on the basis of the unique optical properties of the bulk p-layer that develops on the surface of the H2-plasma treated i-layer. Specifically, an absorption onset near ∼2.5 eV is observed for a 48 Å fully-coalesced p-layer, as measured by RTSE at 200°C. For this μc-Si:H:B p-layer, the optical gap decreases by ∼0.15 eV with increasing thickness from 50 to 200 Å. This effect is attributed to a reduction in the quantum confinement energy with an increase in the average crystallite size in the film.

Spectrally Resolved Fill Factor Measurements on a-Si:H Based Solar Cell Structures

1996 ◽  
Vol 426 ◽  
Author(s):  
Michael Wagner ◽  
Dimitrios Peros ◽  
Stephan Guse ◽  
Markus Böhm
Keyword(s):  
Solar Cell ◽  
Fill Factor ◽  
Charge Compensation ◽  
Open Circuit ◽  
Cell Structures ◽  
Deposition Parameters ◽  
Wide Range ◽  
Current Densities ◽  
Spectrally Resolved ◽  
Hydrogenated Amorphous

AbstractThis work presents essential differences in the fill factors (FF) of pin and nip solar cell structures based on hydrogenated amorphous silicon (a-Si:H). The nomenclature “pin’ (‘nip’ respectively) determines the deposition sequence of the single layers. Fill factor measurements are carried out with illumination through p- and n-layers at different wavelengths. The use of laser light provides a wide range of illumination levels and photo current densities of up to 14mA/cm2. The spectrally resolved FF measurements indicate an incorporation of dopants in the i-layer depending on the layer deposited first. Nip and pin structures generally show opposite FF dispersion when illuminated through the same layer. However, due to the slight n-conductivity of intrinsic a-Si:H material, a weak boron incorporation leads to a net charge compensation in the ilayer. In contrast to other investigations we do not find a significant deviation in the open circuit voltages of the pin and nip devices as long as the deposition parameters of the single layers are identical.

Amorphous solar cell on multilayer of SnO2/ZnO TCO substrate for full spectrum splitting solar cell application

2014 ◽  
Vol 92 (7/8) ◽  
pp. 917-919 ◽  
Author(s):  
Sinae Kim ◽  
Dong-won Kang ◽  
Porponth Sichanugrist ◽  
Makoto Konagai
Keyword(s):  
Solar Cell ◽  
Fill Factor ◽  
Solar Spectrum ◽  
Thin Film Solar Cells ◽  
Total Efficiency ◽  
Full Spectrum ◽  
Solar Cell Application ◽  
Splitting Technique ◽  
Spectrum Splitting ◽  
Hydrogenated Amorphous

To increase the performance of thin film solar cells, the solar spectrum splitting technique has been considered and studied. It was found from the simulation that the total efficiency of nearly 25% can be obtained at the splitting wavelength of 614 nm with the top cell using higher band gap material. The experiment has been carried out to verify the simulation results. Up to now a total efficiency of about 22.0% has been obtained using hydrogenated amorphous silicon (a-Si:H) and Cu(In1–x,Gax) as the top and bottom cells, respectively, at a splitting wavelength of 620 nm. In this study, we have developed a multilayer of transparent and conductive oxide (TCO) substrate of a-Si:H solar cell with better electrical properties especially improved fill factor and better electrical compatibility. This multilayer TCO is suitable for the splitting technique to enhance the performance at the short-wavelength of the top cell.

An expanded isoindigo unit as a new building block for a conjugated polymer leading to high-performance solar cells

2014 ◽  
Vol 2 (15) ◽  
pp. 5427-5433 ◽  
Author(s):  
Shugang Li ◽  
Zhongcheng Yuan ◽  
Jianyu Yuan ◽  
Ping Deng ◽  
Qing Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Building Block ◽  
Conjugated Polymer ◽  
High Performance ◽  
Fill Factor ◽  
Solar Cell Device ◽  
Donor Acceptor ◽  
First Time

An expanded isoindigo unit (IBTI) has been incorporated into a donor–acceptor conjugated polymer for the first time. The PCE of the solar cell device based on the new polymer reached 6.41% with a fill factor of 0.71.

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