Investigation Of Efficiency Improvement on Silicon Solar Cells Due to Porous Layers

1994 ◽  
Vol 358 ◽  
Author(s):  
Gregory Sun ◽  
Yuxin Li ◽  
Yicheng Lu ◽  
Babar Khan ◽  
Gary S. Tompa
Keyword(s):  
Solar Cells ◽  
Porous Layer ◽  
Light Emission ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Porous Si ◽  
Etching Technique ◽  
Shallow Junction ◽  
Si Solar Cells

ABSTRACTObservation of light emission from porous Si has demonstrated that the optical properties of Si can be drastically altered by the quantum size effects. We have investigated the improvement of absorption properties of Si material by forming a porous Si layer. Shallow-junction commercial crystalline as well as polycrystalline Si solar cells without anti-reflective coatings have been processed into porous Si solar cells by a wet chemical etching technique. Our best results have demonstrated more than 15% improvement in short-circuit current with no change in open-circuit voltage. The performance of the porous Si solar cells has been found to be sensitive to the porous layer thickness. The efficiency can be reduced when the porous layer is relatively deep, presumably due to the penetration of pores through the shallow junction. We believe porous Si can be optimized for photovoltaic applications by properly controlling its porosity and thickness.

scholarly journals Analytical Study of the Electrical Output Characteristics of c-Si Solar Cells by Cut and Shading Phenomena

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3397 ◽  
Author(s):  
Jong Lim ◽  
Woo Shin ◽  
Hyemi Hwang ◽  
Young-Chul Ju ◽  
Suk Ko ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Incident Light ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Si Solar Cell ◽  
Si Solar Cells ◽  
Electrical Output

Cut solar cells have received considerable attention recently as they can reduce electrical output degradation when the c-Si solar cells (crystalline-silicon solar cells) are shaded. Cut c-Si solar cells have a lower short-circuit current than normal solar cells and the decrease in short-circuit currents is similar to the shading effect of c-Si solar cells. However, the results of this study’s experiment show that the shadow effect of a c-Si solar cell reduces the V o c (open circuit voltage) in the c-Si solar cell but the V o c does not change when the c-Si solar cell is cut because the amount of incident light does not change. In this paper, the limitations of the electrical power analysis of the cut solar cells were identified when only photo current was considered and the analysis of the electric output of the cut c-Si solar cells was interpreted with a method different from that used in previous analyses. Electrical output was measured when the shaded and cut rates of c-Si solar cells were increased from 0% to 25, 50 and 75%, and a new theoretical model was compared with the experimental results using MATLAB.

Simulation of InAIN/Si Single-Heterojunction Solar Cells Using wxAMPS

2014 ◽  
Vol 665 ◽  
pp. 111-114 ◽  
Author(s):  
Ying Huang ◽  
Xiao Ming Shen ◽  
Xiao Feng Wei
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Indium Content ◽  
Open Circuit ◽  
Heterojunction Solar Cells ◽  
Si Solar Cells

In this paper, InAlN/Si single-heterojunction solar cells have been theoretically simulated based on wxAMPS software. The photovoltaic parameters, such as open circuit voltage, short circuit current, fill factor and conversion efficiency were investigated with changing the indium content and thickness of n-InAlN layer. Simulation results show that the optimum efficiency of InAlN/Si solar cells is 23.1% under AM 1.5G spectral illuminations, with the indium content and thickness of n-InAlN layer are 0.65 and 600nm, respectively. The simulation would contribute to design and fabricate high efficiency InAlN/Si solar cells in experiment.

Photovoltaic Characteristics of Ultra-Thin Single Crystalline Silicon Solar Cells

2016 ◽  
Vol 25 (01n02) ◽  
pp. 1640008
Author(s):  
R. Miyazawa ◽  
H. Wakabayashi ◽  
K. Tsutsui ◽  
H. Iwai ◽  
K. Kakushima
Keyword(s):  
Solar Cells ◽  
Crystalline Silicon ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Response Measurement ◽  
Single Crystalline ◽  
Si Solar Cells ◽  
Photovoltaic Characteristics

Photovoltaic characteristics of ultra-thin single crystalline Si solar cells with thicknesses ranging from 7.6 to 3.3 nm are presented. While the short-circuit current (ISC) AM1.5 illumination has shown a linear relationship with the volume of the Si layer, a gradual increase in the open-circuit voltage (VOC) with thinner Si layer has been confirmed, implying the bandgap enlargement of the Si layer due to quantum confinement. Spectral response measurement has revealed an increased optical bandgap of 1.3 eV for 3.3-nm-thick Si solar cells, which is wider than that of 7.6-nm-thick Si ones. Although some process related issues have become clear during the fabrication of solar cells, they can be utilized as top cells for tandem configurations, exceeding the limit of the bulk Si solar cells.

Fabrication of the Large-Area Integrated a-Si Solar Cells

1986 ◽  
Vol 70 ◽  
Author(s):  
S. Yamazaki ◽  
M. Abe ◽  
S. Nagayama ◽  
K. Shibata ◽  
M. Susukida ◽  
...  
Keyword(s):  
Solar Cells ◽  
Standard Deviation ◽  
Conversion Efficiency ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Process Equipment ◽  
Large Area ◽  
Si Solar Cells

ABSTRACTPIN-structure small-area solar cells using a-Si have been frequently reported on, but only a few reports are available on the study of solar cells using a large-area (10-cm square) substrate, all with a resultant conversion efficiency of above 9.0 %[1,2]. Our study has been concentrated on solar cells using a batch of ten 10-cm square substrates with an average conversion efficiency of 9.5 % or more.As a result, without an anti-reflection coating on the surface of the glass substrate, the following values have been obtained: average conversion efficiency (EFF)=9.63 % (standard deviation of 0.195 %) -Open-circuit voltage (Voc)=12.668 V (standard deviation of 0.215 V) -Short-circuit current (Isc)=78.467 mA (standard deviation of 1.619 mA) -Fill factor (FF)=0.6672 (standard deviation of 0.009)The process, equipment and methods for measurements through which these results were obtained are described below.

scholarly journals CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Early Years ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.

scholarly journals GaInP/GaAs/poly-Si Multi-Junction Solar Cells by in Metal Balls Bonding

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 726
Author(s):  
Ray-Hua Horng ◽  
Yu-Cheng Kao ◽  
Apoorva Sood ◽  
Po-Liang Liu ◽  
Wei-Cheng Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Low Temperature ◽  
Triple Junction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Metal Line ◽  
Solar Simulator ◽  
Junction Solar Cell

In this study, a mechanical stacking technique has been used to bond together the GaInP/GaAs and poly-silicon (Si) solar wafers. A GaInP/GaAs/poly-Si triple-junction solar cell has mechanically stacked using a low-temperature bonding process which involves micro metal In balls on a metal line using a high-optical-transmission spin-coated glue material. Current–voltage measurements of the GaInP/GaAs/poly-Si triple-junction solar cells have carried out at room temperature both in the dark and under 1 sun with 100 mW/cm2 power density using a solar simulator. The GaInP/GaAs/poly-Si triple-junction solar cell has reached an efficiency of 24.5% with an open-circuit voltage of 2.68 V, a short-circuit current density of 12.39 mA/cm2, and a fill-factor of 73.8%. This study demonstrates a great potential for the low-temperature micro-metal-ball mechanical stacking technique to achieve high conversion efficiency for solar cells with three or more junctions.

scholarly journals Ultrathin Cu(In,Ga)Se2 Solar Cells with Ag/AlOx Passivating Back Reflector

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4268
Author(s):  
Jessica de Wild ◽  
Gizem Birant ◽  
Guy Brammertz ◽  
Marc Meuris ◽  
Jef Poortmans ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Electron Microscopic ◽  
Current Increase ◽  
Time Resolved ◽  
Cigs Solar Cells

Ultrathin Cu(In,Ga)Se2 (CIGS) absorber layers of 550 nm were grown on Ag/AlOx stacks. The addition of the stack resulted in solar cells with improved fill factor, open circuit voltage and short circuit current density. The efficiency was increased from 7% to almost 12%. Photoluminescence (PL) and time resolved PL were improved, which was attributed to the passivating properties of AlOx. A current increase of almost 2 mA/cm2 was measured, due to increased light scattering and surface roughness. With time of flight—secondary ion mass spectroscopy, the elemental profiles were measured. It was found that the Ag is incorporated through the whole CIGS layer. Secondary electron microscopic images of the Mo back revealed residuals of the Ag/AlOx stack, which was confirmed by energy dispersive X-ray spectroscopy measurements. It is assumed to induce the increased surface roughness and scattering properties. At the front, large stains are visible for the cells with the Ag/AlOx back contact. An ammonia sulfide etching step was therefore applied on the bare absorber improving the efficiency further to 11.7%. It shows the potential of utilizing an Ag/AlOx stack at the back to improve both electrical and optical properties of ultrathin CIGS solar cells.

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

2018 ◽  
Vol 9 ◽  
pp. 1802-1808 ◽  
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.

scholarly journals Effects of Different Doping Ratio of Cu Doped CdS on QDSCs Performance

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Xiaojun Zhu ◽  
Xiaoping Zou ◽  
Hongquan Zhou
Keyword(s):  
Solar Cells ◽  
Quantum Dot ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Photoelectric Conversion Efficiency ◽  
Photoelectric Conversion ◽  
Sensitized Solar Cells ◽  
Doping Ratio

We use the successive ionic layer adsorption and reaction (SILAR) method for the preparation of quantum dot sensitized solar cells, to improve the performance of solar cells by doping quantum dots. We tested the UV-Vis absorption spectrum of undoped CdS QDSCs and Cu doped CdS QDSCs with different doping ratios. The doping ratios of copper were 1 : 100, 1 : 500, and 1 : 1000, respectively. The experimental results show that, under the same SILAR cycle number, Cu doped CdS quantum dot sensitized solar cells have higher open circuit voltage, short circuit current density photoelectric conversion efficiency than undoped CdS quantum dots sensitized solar cells. Refinement of Cu doping ratio are 1 : 10, 1 : 100, 1 : 200, 1 : 500, and 1 : 1000. When the proportion of Cu and CdS is 1 : 10, all the parameters of the QDSCs reach the minimum value, and, with the decrease of the proportion, the short circuit current density, open circuit voltage, and the photoelectric conversion efficiency are all increased. When proportion is 1 : 500, all parameters reach the maximum values. While with further reduction of the doping ratio of Cu, the parameters of QDSCs have a decline tendency. The results showed that, in a certain range, the lower the doping ratio of Cu, the better the performance of quantum dot sensitized solar cell.

Study of Photoelectrochemical Solar Cell Using WSe2 Crystal

2013 ◽  
Vol 665 ◽  
pp. 330-335 ◽  
Author(s):  
Ripal Parmar ◽  
Dipak Sahay ◽  
R.J. Pathak ◽  
R.K. Shah
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrical Energy ◽  
Open Circuit ◽  
Cell Parameters ◽  
Photoelectrochemical Solar Cell ◽  
Photoelectrochemical Solar Cells

The solar cells have been used as most promising device to convert light energy into electrical energy. In this paper authors have attempted to fabricate Photoelectrochemical solar cell with semiconductor electrode using TMDCs. The Photoelectrochemical solar cells are the solar cells which convert the solar energy into electrical energy. The photoelectrochemical cells are clean and inexhaustible sources of energy. The photoelectrochemical solar cells are fabricated using WSe2crystal and electrolyte solution of 0.025M I2, 0.5M NaI, 0.5M Na2SO4. Here the WSe2crystals were grown by direct vapour transport technique. In our investigations the solar cell parameters like short circuit current (Isc) and Open circuit voltage (Voc) were measured and from that Fill factor (F.F.) and photoconversion efficiency (η) are investigated. The results obtained shows that the value of efficiency and fill factor of solar cell varies with the illumination intensities.

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