The dependence of the crystalline volume fraction on the crystallite size for hydrogenated nanocrystalline silicon based solar cells

2013 ◽  
Vol 1536 ◽  
pp. 113-118 ◽  
Author(s):  
K. J. Schmidt ◽  
Y. Lin ◽  
M. Beaudoin ◽  
G. Xia ◽  
S. K. O'Leary ◽  
...  
Keyword(s):  
Solar Cells ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Nanocrystalline Silicon ◽  
Oxygen Impurity ◽  
Crystalline Volume Fraction ◽  
Three Samples ◽  
Crystallite Sizes ◽  
Silicon Based ◽  
The Impact

ABSTRACTWe have performed an analysis on three hydrogenated nanocrystalline silicon (nc-Si:H) based solar cells. In order to determine the impact that impurities play in shaping the material properties, the XRD and Raman spectra corresponding to all three samples were measured. The XRD results, which displayed a number of crystalline silicon-based peaks, were used in order to approximate the mean crystallite sizes through Scherrer's equation. Through a peak decomposition process, the Raman results were used to estimate the corresponding crystalline volume fraction. It was noted that small crystallite sizes appear to favor larger crystalline volume fractions. This dependence seems to be related to the oxygen impurity concentration level within the intrinsic nc-Si:H layers.

The mean crystallite size within a hydrogenated nanocrystalline silicon based photovoltaic solar cell and its role in determining the corresponding crystalline volume fraction

2014 ◽  
Vol 92 (7/8) ◽  
pp. 857-861 ◽  
Author(s):  
K.J. Schmidt ◽  
Y. Lin ◽  
M. Beaudoin ◽  
G. Xia ◽  
S.K. O’Leary ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Volume Fraction ◽  
Nanocrystalline Silicon ◽  
Crystalline Volume Fraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photovoltaic Solar Cell ◽  
Crystallite Sizes ◽  
The Mean ◽  
Silicon Based

We examine the dependence of the crystalline volume fraction on the mean crystallite size for hydrogenated nanocrystalline silicon based photovoltaic solar cells; this work builds upon an earlier study by Schmidt et al. (Mater. Res. Soc. Symp. Proc. 1536 (2013)). For each photovoltaic solar cell considered, the X-ray diffraction and Raman spectra are measured. Through the application of Scherrer’s equation, the X-ray diffraction results are used to determine the corresponding mean crystallite sizes. Through peak decomposition, the Raman results are used to estimate the corresponding crystalline volume fraction. Plotting the crystalline volume fraction as a function of the mean crystallite size, it is found that larger mean crystallite sizes tend to favor reduced crystalline volume fractions. The ability to randomly pack smaller crystallites with a greater packing fraction than their larger counterparts was suggested as a possible explanation for this observation.

Research on Nanocrystalline Silicon Film Solar Cells

2011 ◽  
Vol 347-353 ◽  
pp. 870-873
Author(s):  
Chun Rong Xue
Keyword(s):  
Grain Size ◽  
Solar Cells ◽  
Band Gap ◽  
Optical Band Gap ◽  
Volume Fraction ◽  
Silicon Film ◽  
Nanocrystalline Silicon ◽  
Processing Parameters ◽  
Crystalline Volume Fraction ◽  
Hydrogen Dilution

Nanocrystalline silicon film has become the research hit of today’ s P-V solar technology. It’s optical band gap was controlled through changing the grain size and crystalline volume fraction for the quanta dimension effect. The crystalline volume fraction in nc-Si:H is modulated by varying the hydrogen concentration in the silane plasma. Also, the crystallinity of the material increases with increasing hydrogen dilution ratio, the band tail energy width of the nc-Si:H concurrently decreases. Two sets of nc-Si:H solar cells were made with different layer thicknesss, their electronic and photonic bandgap, absorption coefficient, optical band gap, nanocrystalline grain size(D), and etc have been stuied. In addition, we discussed the relationship between the stress of nc-Si thin films and H2 ratio. At last nc-Si:H solar cells have been designed and prepared successfully in the optimized processing parameters.

scholarly journals Key Success Factors and Future Perspective of Silicon-Based Solar Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. Binetti ◽  
M. Acciarri ◽  
A. Le Donne ◽  
M. Morgano ◽  
Y. Jestin
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Success Factors ◽  
Crystalline Silicon ◽  
Control Device ◽  
Future Perspective ◽  
Cost Ratio ◽  
Silicon Technology ◽  
Silicon Based ◽  
The Impact

Today, after more than 70 years of continued progress on silicon technology, about 85% of cumulative installed photovolatic (PV) modules are based on crystalline silicon (c-Si). PV devices based on silicon are the most common solar cells currently being produced, and it is mainly due to silicon technology that the PV has grown by 40% per year over the last decade. An additional step in the silicon solar cell development is ongoing, and it is related to a further efficiency improvement through defect control, device optimization, surface modification, and nanotechnology approaches. This paper attempts to briefly review the most important advances and current technologies used to produce crystalline silicon solar devices and in the meantime the most challenging and promising strategies acting to increase the efficiency to cost/ratio of silicon solar cells. Eventually, the impact and the potentiality of using a nanotechnology approach in a silicon-based solar cell are also described.

Nano-Crystalline Si Based Alloy (nc-SiXY) with Band Gap of 1.5 eV as the Solar Cell Absorber Layer Fabricated by VHF-PECVD Technique

2012 ◽  
Vol 1426 ◽  
pp. 87-92
Author(s):  
Feng Zhu ◽  
Jian Hu ◽  
Ilvydas Matulionis ◽  
Josh Gallon ◽  
Arun Madan
Keyword(s):  
Volume Fraction ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Optical Bandgap ◽  
Absorber Layer ◽  
Crystalline Volume Fraction ◽  
Very High Frequency ◽  
Nano Crystalline ◽  
Silicon Based ◽  
Gas Ratio

ABSTRACTWe describe the properties of nano-crystalline silicon based alloy (nc-SiXY) prepared by a very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) technique with silane (SiH4) and XY gas mixtures and diluted in hydrogen (H2) at low deposition temperature. Varying the gas ratio among SiH4, H2 and XY gasses could alter the optical bandgap and structure. The nc-Si films with high crystalline volume fraction were first prepared, and then the XY gasses were added in order to tune the microstructure and opto-electronic properties of this nano-crystalline silicon based alloy. We have characterized the materials using UV-VIS-NIR, Raman, Constant Photocurrent Method (CPM), dark- and photo-conductivity. As XY gas flows were increased, the optical bandgap of nc-SiXY films increased, while its crystalline volume fraction and conductivity decreased. With proper control of the silane concentration, XY/SiH4 gas ratio, and deposition pressure, we have fabricated the nc-SiXY film with optical bangap of about 1.5eV. Applying this material as the absorber layer in p-i-n devices with configuration of textured ZnO/nc-p+/nc-SiXY/a-n+/Ag, the efficiency is 7.25% (Voc=0.616V, Jsc=17.69mA/cm2, FF= 0.666) with thickness of ∼0.8μm.

Characterization of the Mobility Gap in μc-Si:H Pin Devices

2008 ◽  
Vol 1066 ◽  
Author(s):  
Bart Elger Pieters ◽  
Sandra Schicho ◽  
Helmut Stiebig
Keyword(s):  
Solar Cells ◽  
Dark Current ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Crystalline Volume Fraction ◽  
A Value ◽  
Current Activation ◽  
Crystalline Solar Cell ◽  
Mobility Gap

ABSTRACTFor the mobility gap of hydrogenated micro-crystalline silicon (μc-Si:H) a value near 1.1 eV is commonly found, similar to the bandgap of crystalline silicon. However, in other studies mobility gap values have been reported to be in the range of 1.48-1.59 eV. Indeed, for accurate modeling of μc-Si:H solar cells it is paramount that key parameters like the mobility gap are accurately determined. In this work we will discuss a method to determine the mobility gap of μc-Si:H using the dark current activation energy of μc-Si:H pin devices, and apply this method to μc-Si:H solar cells with varying crystalline volume fraction. We found the mobility gap is around 1.2 eV to 1.26 eV for μc-Si:H solar cells with a crystalline volume fraction between 50 % and 70 %. For a highly crystalline solar cell we found a mobility gap of 1.07 eV.

p-type nc-SiOx:H emitter layer for silicon heterojunction solar cells grown by rf-PECVD

2015 ◽  
Vol 1770 ◽  
pp. 7-12 ◽  
Author(s):  
Henriette A. Gatz ◽  
Yinghuan Kuang ◽  
Marcel A. Verheijen ◽  
Jatin K. Rath ◽  
Wilhelmus M.M. (Erwin) Kessels ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Material Properties ◽  
Crystalline Silicon ◽  
Silicon Layer ◽  
Nanocrystalline Silicon ◽  
Emitter Layer ◽  
Heterojunction Solar Cells ◽  
P Type ◽  
Silicon Heterojunction Solar Cells

ABSTRACTSilicon heterojunction solar cells (SHJ) with thin intrinsic layers are well known for their high efficiencies. A promising way to further enhance their excellent characteristics is to enable more light to enter the crystalline silicon (c-Si) absorber of the cell while maintaining a simple cell configuration. Our approach is to replace the amorphous silicon (a-Si:H) emitter layer with a more transparent nanocrystalline silicon oxide (nc-SiOx:H) layer. In this work, we focus on optimizing the p-type nc-SiOx:H material properties, grown by radio frequency plasma enhanced chemical vapor deposition (rf PECVD), on an amorphous silicon layer.20 nm thick nanocrystalline layers were successfully grown on a 5 nm a-Si:H layer. The effect of different ratios of trimethylboron to silane gas flow rates on the material properties were investigated, yielding an optimized material with a conductivity in the lateral direction of 7.9×10-4 S/cm combined with a band gap of E04 = 2.33 eV. Despite its larger thickness as compared to a conventional window a-Si:H p-layer, the novel layer stack of a-Si:H(i)/nc-SiOx:H(p) shows significantly enhanced transmission compared to the stack with a conventional a-Si:H(p) emitter. Altogether, the chosen material exhibits promising characteristics for implementation in SHJ solar cells.

scholarly journals The Role of Silicon Heterojunction and TCO Barriers on the Operation of Silicon Heterojunction Solar Cells: Comparison between Theory and Experiment

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yaser Abdulraheem ◽  
Moustafa Ghannam ◽  
Hariharsudan Sivaramakrishnan Radhakrishnan ◽  
Ivan Gordon
Keyword(s):  
Solar Cells ◽  
Large Scale ◽  
Surface Passivation ◽  
Series Resistance ◽  
Crystalline Silicon ◽  
Thermionic Emission ◽  
Analytical Description ◽  
Theoretical Explanation ◽  
The Impact

Photovoltaic devices based on amorphous silicon/crystalline silicon (a-Si:H/c-Si) heterojunction interfaces hold the highest efficiency as of date in the class of silicon-based devices with efficiencies exceeding 26% and are regarded as a promising technology for large-scale terrestrial PV applications. The detailed understanding behind the operation of this type of device is crucial to improving and optimizing its performance. SHJ solar cells have primarily two main interfaces that play a major role in their operation: the transparent conductive oxide (TCO)/a-Si:H interface and the a-Si:H/c-Si heterojunction interface. In the work presented here, a detailed analytical description is provided for the impact of both interfaces on the performance of such devices and especially on the device fill factor ( FF ). It has been found that the TCO work function can dramatically impact the FF by introducing a series resistance element in addition to limiting the forward biased current under illumination causing the well-known S-shape characteristic in the I-V curve of such devices. On the other hand, it is shown that the thermionic emission barrier at the heterojunction interface can play a major role in introducing an added series resistance factor due to the intrinsic a-Si:H buffer layer that is usually introduced to improve surface passivation. Theoretical explanation on the role of both interfaces on device operation based on 1D device simulation is experimentally verified. The I-V characteristics of fabricated devices were compared to the curves produced by simulation, and the observed degradation in the FF of fabricated devices was explained in light of analytical findings from simulation.

scholarly journals Numerical Design of Ultrathin Hydrogenated Amorphous Silicon-Based Solar Cell

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
F. X. Abomo Abega ◽  
A. Teyou Ngoupo ◽  
J. M. B. Ndjaka
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Buffer Layer ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Theoretical Work ◽  
Silicon Based ◽  
The Impact ◽  
Hydrogenated Amorphous

Numerical modelling is used to confirm experimental and theoretical work. The aim of this work is to present how to simulate ultrathin hydrogenated amorphous silicon- (a-Si:H-) based solar cells with a ITO BRL in their architectures. The results obtained in this study come from SCAPS-1D software. In the first step, the comparison between the J-V characteristics of simulation and experiment of the ultrathin a-Si:H-based solar cell is in agreement. Secondly, to explore the impact of certain properties of the solar cell, investigations focus on the study of the influence of the intrinsic layer and the buffer layer/absorber interface on the electrical parameters ( J SC , V OC , FF, and η ). The increase of the intrinsic layer thickness improves performance, while the bulk defect density of the intrinsic layer and the surface defect density of the buffer layer/ i -(a-Si:H) interface, respectively, in the ranges [109 cm-3, 1015 cm-3] and [1010 cm-2, 5 × 10 13  cm-2], do not affect the performance of the ultrathin a-Si:H-based solar cell. Analysis also shows that with approximately 1 μm thickness of the intrinsic layer, the optimum conversion efficiency is 12.71% ( J SC = 18.95   mA · c m − 2 , V OC = 0.973   V , and FF = 68.95 % ). This work presents a contribution to improving the performance of a-Si-based solar cells.

The Use of Lasers at Various Stages of the Manufacturing Process of Solar Cells Based on Crystalline Silicon

2020 ◽  
Vol 308 ◽  
pp. 138-156
Author(s):  
Małgorzata Musztyfaga-Staszuk ◽  
Piotr Panek
Keyword(s):  
Solar Cells ◽  
Laser Radiation ◽  
Crystalline Silicon ◽  
Point Contact ◽  
Radiation Energy ◽  
Photovoltaic Cell ◽  
Materials Engineering ◽  
University Of Technology ◽  
Academy Of Sciences ◽  
The Impact

The purpose of this chapter of the book is to present knowledge on the use of laser technology in silicon photovoltaic cell manufacturing processes. Particular consideration was given to the technique of using a disk laser to cut the edges of silicon wafers together with the recognition of the flow of laser micromachining on the quality of cut edges to obtain their minimal deformation. The second topic described is the method of producing point contacts employing laser radiation between a layer of vaporised aluminium and crystalline silicon using the Nd:YAG laser. The results illustrating the impact of the structure and parameters of point contact for a given laser radiation energy on basic electrical parameters for complete, prototype solar cells are included. The chapter in the book provides an overview of the literature on the above topics and presents selected results of experimental works carried out by the authors. The motive for its publication is the need to present selected results of own research carried out in the Welding Department cooperating for many years with the Institute of Engineering and Biomedical Materials (IMIiB) of the Silesian University of Technology and the Institute of Metallurgy and Materials Engineering (IMIM) of the Polish Academy of Sciences in Cracow.

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