p-type Window Layers for pin Solar Cells Entirely Fabricated by Hot-Wire CVD

2001 ◽  
Vol 664 ◽  
Author(s):  
Urban Weber ◽  
Markus Koob ◽  
Chandrachur Mukherjee ◽  
D. Chandrashekhar ◽  
Rajiv O. Dusane
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Dark Conductivity ◽  
Hot Wire ◽  
Hydrocarbon Gases ◽  
Layer Deposition ◽  
The Stability ◽  
Direct Dissociation

ABSTRACTWe investigate a-SiC:H p-layer deposition for a-Si:H-based solar cells by Hot-Wire CVD using alternatively methane, ethane, and acetylene. Carbon incorporation in the film results from gas-phase reactions and not from direct dissociation at the hot filament for all hydrocarbon gases. Ethane can be dissociated more easily than methane allowing less extreme deposition conditions. With all types of materials the requirements of high dark conductivity and high band gap for the use as window layers in solar cells can be fulfilled. Highest conductivity is observed with ethane indicating a better network structure, which is supported by the IR signatures. A larger band gap (>2 eV) can be obtained at a similar conductivity with the use of acetylene. We compare these results with the utilization of [.proportional]c-Si:H p-layers. All types of p-layers are incorporated into pin solar cells. Methane- and ethane-based a-SiC:H-p-layers yield similar Voc and FF (∼850 mV and 72%). Acetylene-p-layer-based solar cells yield higher current and higher Voc (890 mV) but lower fill factor (∼67%). Microcrystalline p-layers improve Voc and FF up to 900 mV and 72%, respectively, however higher absorption leads to lower short circuit current and prevents an increase of initial efficiency beyond 8%. Using ethane for p-layer deposition, a significant improvement of the stability of all-Hot-Wire CVD pin solar cells is achieved.

Various Applications of Multifunctional Thin Films with Specific Properties Deposited by the ALD Method

2019 ◽  
Vol 293 ◽  
pp. 111-123
Author(s):  
Paulina Boryło ◽  
Marek Szindler ◽  
Krzysztof Lukaszkowicz
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Atomic Layer ◽  
Short Circuit Current ◽  
Transparent Conductive Oxide ◽  
Atomic Force ◽  
Layer Deposition ◽  
Atomic Layer Deposition Method

This paper presents application examples of atomic layer deposition method (ALD) adopted for production of multifunctional thin films for various usage such as passive, antireflection and transparent conductive films. First part of this paper introduces the mechanism of ALD process, in the rest of it, aluminum oxide (as passive and antireflection) and zinc oxide (as antireflection and transparent conductive) ALD thin films are presented. In the literature one can find reports on the use of the Al2O3 layer as passivating and ZnO layers as a transparent conductive oxide in diodes, polymeric and dye sensitized solar cells. In this article, the ALD layers were tested for their use in silicon solar cells, using their good electrical and optical properties. For examination of prepared thin films characteristics, following research methods were used: scanning electron microscope, atomic force microscope, X-ray diffractometer, ellipsometer, UV/VIS spectrometer and resistance measurements. By depositing a layer thickness of about 80 nm, the short-circuit current on the surface of the solar cell was increased three times while reducing the reflection of light. In turn, by changing the deposition temperature of the ZnO thin film, you can control its electrical properties while maintaining high transparency. The obtained results showed that the ALD method provide the ability to produce a high quality multifunctional thin films with the required properties.

Hydrogenated Microcrystalline Silicon Solar Cells Made with Modified Very-High-Frequency Glow Discharge

2002 ◽  
Vol 715 ◽  
Author(s):  
Baojie Yan ◽  
Kenneth Lord ◽  
Jeffrey Yang ◽  
Subhendu Guha ◽  
Jozef Smeets ◽  
...  
Keyword(s):  
Solar Cells ◽  
Glow Discharge ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Area Efficiency ◽  
Double Junction ◽  
Stability Data ◽  
The Stability

AbstractHydrogenated microcrystalline silicon (μc-Si:H) solar cells are made using modified veryhigh-frequency (MVHF) glow discharge at deposition rates ∼3-5 Å/s. We find that the solar cells made under certain conditions show degradation in air without intentional light soaking. The short-circuit current drops significantly within a few days after deposition, and then stabilizes. We believe that post-deposition oxygen diffusion along the grain boundaries or cracks is the origin of the ambient degradation. By optimizing the deposition conditions, we have found a plasma regime in which the μc-Si:H solar cells do not show such ambient degradation. The best a-Si:H/μc-Si:H double-junction solar cell has an initial active-area efficiency of 10.9% and is stable against the ambient degradation. The stability data of the solar cells after light soaking are also presented.

scholarly journals Graded Carrier Concentration Absorber Profile for High Efficiency CIGS Solar Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Antonino Parisi ◽  
Riccardo Pernice ◽  
Vincenzo Rocca ◽  
Luciano Curcio ◽  
Salvatore Stivala ◽  
...  
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Carrier Concentration ◽  
High Efficiency ◽  
Energy Gap ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Doping Density ◽  
Cigs Solar Cells

We demonstrate an innovative CIGS-based solar cells model with a graded doping concentration absorber profile, capable of achieving high efficiency values. In detail, we start with an in-depth discussion concerning the parametrical study of conventional CIGS solar cells structures. We have used the wxAMPS software in order to numerically simulate cell electrical behaviour. By means of simulations, we have studied the variation of relevant physical and chemical parameters—characteristic of such devices—with changing energy gap and doping density of the absorber layer. Our results show that, in uniform CIGS cell, the efficiency, the open circuit voltage, and short circuit current heavily depend on CIGS band gap. Our numerical analysis highlights that the band gap value of 1.40 eV is optimal, but both the presence of Molybdenum back contact and the high carrier recombination near the junction noticeably reduce the crucial electrical parameters. For the above-mentioned reasons, we have demonstrated that the efficiency obtained by conventional CIGS cells is lower if compared to the values reached by our proposed graded carrier concentration profile structures (up to 21%).

Hydrogenated amorphous silicon germanium by Hot Wire CVD as an alternative for microcrystalline silicon in tandem and triple junction solar cells

2014 ◽  
Vol 1666 ◽  
Author(s):  
L.W. Veldhuizen ◽  
Y. Kuang ◽  
N.J. Bakker ◽  
C.H.M. van der Werf ◽  
S.-J. Yun ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Silicon Germanium ◽  
Short Circuit ◽  
Hydrogenated Amorphous Silicon ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous

ABSTRACTWe study hydrogenated amorphous silicon germanium (a-SiGe:H) deposited by HWCVD for the use as low band gap absorber in multijunction junction solar cells. We deposited layers with Tauc optical band gaps of 1.21 to 1.56 eV and studied the hydrogen bonding with FTIR for layers that were deposited at several reaction pressures. For our reaction conditions, we found an optimal reaction pressure of 38 µbar. The material that is obtained under these conditions does not meet all device quality requirements for a-SiGe:H, which is, as we hypothesize, caused by the presence of He that is used to dilute the GeH4 source gas. We present an initial single junction n-i-p solar cell with a Tauc optical band gap of 1.45 eV and a short circuit current density of 18.7 mA/cm2.

scholarly journals The Band Structures of Zn1−xMgxO(In) and the Simulation of CdTe Solar Cells with a Zn1−xMgxO(In) Window Layer by SCAPS

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 291
Author(s):  
Xu He ◽  
Lili Wu ◽  
Xia Hao ◽  
Jingquan Zhang ◽  
Chunxiu Li ◽  
...  
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Conduction Band ◽  
Short Circuit ◽  
Wavelength Region ◽  
Short Circuit Current ◽  
Window Layer ◽  
Short Wavelength Region ◽  
Conduction Band Offset ◽  
Cdte Solar Cells

Wider band-gap window layers can enhance the transmission of sunlight in the short-wavelength region and improve the performance of CdTe solar cells. In this work, we investigated the band structure of In-doped Zn1−xMgxO (ZMO:In) by using first-principles calculations with the GGA + U method and simulated the performance of ZMO:In/CdTe devices using the SCAPS program. The calculation results show that with the increased Mg doping concentration, the band gap of ZMO increases. However, the band gap of ZMO was decreased after In incorporation due to the downwards shifted conduction band. Owing to the improved short circuit current and fill factor, the conversion efficiency of the ZMO:In-based solar cells show better performance as compared with the CdS-based ones. A highest efficiency of 19.63% could be achieved owing to the wider band gap of ZMO:In and the appropriate conduction band offset (CBO) of ~0.23 eV at ZMO:In/CdTe interface when the Mg concentration x approaches 0.0625. Further investigations on thickness suggest an appropriate thickness of ZMO:In (x = 0.0625) in order to obtain better device performance would be 70–100 nm. This work provides a theoretical guidance for designing and fabricating highly efficient CdTe solar cells.

scholarly journals Review of CdTe1−xSex Thin Films in Solar Cell Applications

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 520 ◽  
Author(s):  
Lingg ◽  
Buecheler ◽  
Tiwari
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Band Gap ◽  
Material Properties ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Thin Film Solar Cells ◽  
Device Structures

Recent improvements in CdTe thin film solar cells have been achieved by using CdTe1−xSex as a part of the absorber layer. This review summarizes the published literature concerning the material properties of CdTe1−xSex and its application in current thin film CdTe photovoltaics. One of the important properties of CdTe1−xSex is its band gap bowing, which facilitates a lowering of the CdTe band gap towards the optimum band gap for highest theoretical efficiency. In practice, a CdTe1−xSex gradient is introduced to the front of CdTe, which induces a band gap gradient and allows for the fabrication of solar cells with enhanced short-circuit current while maintaining a high open-circuit voltage. In some device structures, the addition of CdTe1−xSex also allows for a reduction in CdS thickness or its complete elimination, reducing parasitic absorption of low wavelength photons.

scholarly journals Theoretical analysis of CZTS/CZTSSe tandem solar cells.

2021 ◽  
Author(s):  
Atul Kumar
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Theoretical Analysis ◽  
Band Gap ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Alternative Technique ◽  
Tandem Solar Cells ◽  
Bottom Cell

Abstract Kesterite CZTSxSe1−x has a band gap range from 1 to 1.5eV depending upon S/Se ration. The tandem of kieserite solar cell is proposed and simulated in SCAPS-1D for device configuration and analysis of the performance. CZTS of bandgap 1.5eV as top cell and CZTSSe of bandgap 1.1eV as bottom cell are stacked in tandem for the structure. The thickness of the two layer are optimized for matching the short circuit current JSC in the tandem. This study shines light on alternative technique of thin film multijunction for enhancing the efficiency of CZTSxSe1−x solar cells.

Triple Junction n-i-p Solar Cells with Hot-Wire Deposited Protocrystalline and Microcrystalline Silicon

2007 ◽  
Vol 989 ◽  
Author(s):  
Ruud E.I. Schropp ◽  
Hongbo Li ◽  
Ronald H.J. Franken ◽  
Jatindra K. Rath ◽  
Karine van der Werf ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Solar Cells ◽  
Current Density ◽  
Triple Junction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Hot Wire ◽  
Single Junction ◽  
Long Wavelength ◽  
Back Reflector

AbstractWe have implemented a number of methods to improve the performance of proto-Si/proto-SiGe/μc-Si:H triple junction n-i-p solar cells in which the top and bottom cell i-layers are deposited by Hot-Wire CVD. Firstly, a significant current enhancement is obtained by using textured Ag/ZnO back contacts developed in house instead of plain stainless steel. We studied the correlation between the integrated current density in the long wavelength range (650-1000 nm) with the back reflector surface roughness and clarified that the rms roughness from 2D AFM images correlates well with the long wavelength response of the cell when weighted with a Power Spectral Density function. For single junction 2-μm thick μc-Si:H n-i-p cells we improved the short circuit current density from the value of 15.2 mA/cm2 for plain stainless steel to 23.4 mA/cm2 for stainless steel coated with a textured Ag/ZnO back reflector.Secondly, we optimized the μc-Si:H n-type doped layer on this rough back reflector, the n/i interface, and in addition used a profiling scheme for the H2/SiH4 ratio during i-layer deposition. The H2 dilution during growth was stepwise increased in order to prevent a transition to amorphous growth. The efficiency that was reached for a single junction μc-Si:H n-i-p cell was 8.5%, which is the highest reported value for hot-wire deposited cells of this kind, whereas the deposition rate of 2.1 Å/s is about twice as high as in record cells of this type so far. Moreover, these cells show to be totally stable under light-soaking tests.Combining the above techniques, a rather thin triple junction cell (total silicon thickness 2.5 μm) has been obtained with an efficiency of 10.9%. Preliminary light-soaking tests show that this type of triple cells degrades by less than 4%.

Polyamino acid interlayer facilitates electron extraction in narrow band gap fullerene-free organic solar cells with an outstanding short-circuit current

Nano Energy ◽  
2018 ◽  
Vol 50 ◽  
pp. 169-175 ◽  
Author(s):  
Zhong Zheng ◽  
Rong Wang ◽  
Huifeng Yao ◽  
Shenkun Xie ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Organic Solar Cells ◽  
Narrow Band ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Polyamino Acid ◽  
Electron Extraction
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