Improved Amorphous Silicon Solar Cells Using RPCVD

1993 ◽  
Vol 297 ◽  
Author(s):  
Kyu Chang Park ◽  
Tae Gon Kim ◽  
Sung Ki Kim ◽  
Sung Chul Kim ◽  
Myung Hak Hwang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Narrow Band ◽  
Silicon Solar Cells ◽  
Microcrystalline Silicon ◽  
Preparation Conditions ◽  
Silicon Carbon ◽  
Silicon Silicon

We have studied the depositions of amorphous silicon, silicon carbon alloy, doped microcrystalline silicon in order to apply these films as the component materials for the p-i-n and double stacked solar cells. We have obtained low band gap a-Si:H by decreasing the deposition rate under the proper preparation conditions and highly conductive, thin microcrystalline Si and SiC layers. We have developed a stable a-Si/a-Si double stacked solar cell with a conversion efficiency of ∼ % using narrow band gap a-Si:H as a i-layer of bottom cell.The performance of this cell does not degrade until 100 hrs illumination under 350 mW/cm2.

Performance Enhancement by the Introduction of Additional Narrow Band Gap Bottom Layer of aSi0.64Ge0.36: H on Proposed p + aSi:H/i-aSi: H/n+ aSi0.73Ge0.27: H Thin Film Solar Cells

2020 ◽  
Vol 15 (4) ◽  
pp. 487-497 ◽  
Author(s):  
J. Fatima Rasheed ◽  
V. Suresh Babu
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Current Density ◽  
Narrow Band ◽  
Bottom Layer ◽  
Maximum Power ◽  
Maximum Power Point ◽  
Power Point

This work is the continuation of our previous work entitled "Investigations on optical, material and electrical properties of aSi:H and aSiGe:H in making proposed n+aSi:H/iaSi:H/p+aSiGe:H graded band gap solar cells." In this work, we present an additional bottom layer made of increased germanium content: aSi0.64Ge0.36:H to the previously recommended p+aSi:H/i-aSi:H/n+aSi0.73Ge0.27:H photovoltaic cell to strengthen the absorption spectrum and thereby boosting the attainment of the solar cell. Moreover, the overall active layer thickness is reduced from 430 nm of previous work to 395 nm of proposed work. This work includes the fabrication of samples of epitaxially grown aSiGe:H thin films of varying band gap made with Plasma Enhanced Chemical Vapour Deposition (PECVD) technique succeeded by their characterisation. The establishment of band gap tailoring by varying the germane (GeH4) gas flow rate is thoroughly investigated through optical characterisation. The growth chemistry of PECVD made aSi0.64Ge0.36:H layer has been analysed and the presence of respective radicals has been verified using Fourier Transform Infra Red (FTIR) spectroscopy. In accordance with the measured band gaps, p+ aSi:H/i-aSi:H/n+aSi0.73Ge0.27:H/naSi0.64Ge0.36:H solar cell has been proposed. A comprehensive inquiry on optimisation of the recommended structure has been made by varying the optical band gap and thickness of the bottom most aSi0.64Ge0.36:H layer of the structure. All the cell parameters including open circuit voltage (Voc), short circuit current density (Jsc), maximum power point voltage (Vm), maximum power point current density (Jm), Fill factor (FF) and conversion efficiency (η) has been calculated using SCAPS1D solar simulator. Furthermore, C–V characteristics and Mott-Schottky plot of the proposed structure has been evaluated. The introduction of narrow band gap amorphous silicon germanium (aSi0.64Ge0.36:H) at the bottom has remarkably enhanced Jsc and η to 15.54 mA/cm2 and 15.15% respectively, which is better compared to reported amorphous silicon photovoltaic cells having single junction.

Stable Solar Cells Prepared from Dichlorosilane

1998 ◽  
Vol 507 ◽  
Author(s):  
Y. Yamamoto ◽  
W. Futako ◽  
K. Fukutani ◽  
M. Hagino ◽  
T. Sugawara ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Buffer Layers ◽  
Silicon Solar Cells ◽  
Hydrogen Dilution ◽  
Cell Structures ◽  
Reactive Plasma ◽  
Plasma Species

ABSTRACTAmorphous silicon films and solar cell i-layers were prepared from dichlorosilane(DCS) by ECR- and VHF-CVD. The hydrogen content, the chlorine content and the band gap could be controlled by varying argon and hydrogen dilution. The interaction of energetic and reactive plasma species with substrates and other previously deposited layers was studied. DCS, ECR-CVD causes darkening of TCO substrates even when buffer layers and/or doped layers were previously deposited by RF-CVD. Therefore n-i-p solar cell structures were prepared on NiCr and subsequent p-i-n solar cells were prepared with VHF-CVD which did not causeTCO reduction or other reactions in previously deposited amorphous layers. Preliminary results indicate that the VHF-CVD solar cells are at least as stable as standard amorphous silicon solar cells.

Model-based Quantitative Assessment of Crystallinity and Parasitic Absorption in Microcrystalline Silicon Solar Cells

2012 ◽  
Vol 1426 ◽  
pp. 383-387
Author(s):  
Thomas Lanz ◽  
Corsin Battaglia ◽  
Christophe Ballif ◽  
Beat Ruhstaller
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Light Scattering ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Quantitative Assessment ◽  
Silicon Solar Cells ◽  
Normalization Procedure ◽  
Microcrystalline Silicon ◽  
Scattering Model

ABSTRACTWe investigate the influence of the crystallinity of the absorber layer and parasitic absorption in the doped layers and electrodes on the external quantum efficiency and reflection of microcrystalline silicon (μc-Si:H) solar cells. Using an optical light scattering model we systematically study variations in the crystallinity and validate a simple normalization procedure that allows assessing the gains that can be achieved by reducing the parasitic absorption. The optimization potential is demonstrated with solar cell samples with increased crystallinity and eliminated parasitic absorption.

Periodic Structures for Improved Light Management in Thin-film Silicon Solar Cells

2008 ◽  
Vol 1101 ◽  
Author(s):  
Janez Krc ◽  
Andrej Campa ◽  
Stefan L. Luxembourg ◽  
Miro Zeman ◽  
Marko Topic
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Photonic Crystal ◽  
Amorphous Silicon ◽  
Periodic Structures ◽  
Light Trapping ◽  
Silicon Solar Cells ◽  
Thin Film Silicon ◽  
Light Management

AbstractAdvanced light management in thin-film solar cells is important in order to improve the photo-current and, thus, to raise up the conversion efficiencies of the solar cells. In this article two types of periodic structures ¡V one-dimensional diffraction gratings and photonic crystals,are analyzed in the direction of showing their potential for improved light trapping in thin-film silicon solar cells. The anti-reflective effects and enhanced scattering at the gratings with the triangular and rectangular features are studied by means of two-dimensional optical simulations. Simulations of the complete microcrystalline solar cell incorporating the gratings at all interfaces are presented. Critical optical issues to be overcome for achieving the performances of the cells with the optimized randomly textured interfaces are pointed out. Reflectance measurements for the designed 12 layer photonic crystal stack consisting of amorphous silicon nitride and amorphous silicon layers are presented and compared with the simulations. High reflectance (up to 99 %) of the stack is measured for a broad wavelength spectrum. By means of optical simulations the potential for using a simple photonic crystal structure as a back reflector in an amorphous silicon solar cell is demonstrated.

Amorphous Silicon-Carbon Alloys for Solar Cells

1993 ◽  
Vol 297 ◽  
Author(s):  
Yuan-Min Li
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Light Exposure ◽  
Open Circuit ◽  
Hydrogen Dilution ◽  
Silicon Carbon ◽  
Hydrogenated Amorphous ◽  
Substrate Temperatures ◽  
Open Circuit Voltages

Recent efforts to optimize undoped, glow-discharge hydrogenated amorphous silicon-carbon alloys (a-SiC:H) with 1.9-2.0 eV bandgaps for solar cell applications are reviewed. Hydrogen dilution coupled with relatively low substrate temperatures (below 200 °C) have led to great improvements in the optical and phototransport properties of a-SiC:H films. The issue of alternative carbon feedstocks other than methane (CH4) will be explored. The improved a-SiC:H alloys have resulted in solar cells with high open circuit voltages (V∞ > 1.0 volt) and high fill factors (> 0.7). Further, the a-SiC:H solar cell instability upon prolonged light exposure has been much reduced. Correlation will be made between the properties of bulk undoped a-SiC:H films and the performance of p-i-nsingle junction solar cells using corresponding a-SiC:H thin i-layers.

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