Amorphous Silicon Alloy Materials and Solar Cells Near the Threshold of Microcrystallinity

1999 ◽  
Vol 557 ◽  
Author(s):  
J. Yang ◽  
S. Guha
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Triple Junction ◽  
High Efficiency ◽  
Spectral Response ◽  
High Quality ◽  
Silicon Alloys ◽  
Solar Cell Performance ◽  
Hydrogen Dilution

AbstractOne of the most effective techniques used to obtain high quality amorphous silicon alloys is the use of hydrogen dilution during film growth. The resultant material exhibits a more ordered microstructure and gives rise to high efficiency solar cells. As the hydrogen dilution increases, however, a threshold is reached, beyond which microcrystallites begin to form rapidly. In this paper, we review some of the interesting features associated with the thin film materials obtained from various hydrogen dilutions. They include the observation of linear-like objects in the TEM micrograph, a shift of the principal Si TO band in the Raman spectrum, a sharp, low temperature peak in the H2 evolution spectrum, a shift of the wagging mode in the IR spectrum, and a narrowing of the Si (111) peak in the X-ray diffraction pattern. These spectroscopic tools have allowed us to optimize deposition conditions to near the threshold of microcrystallinity and obtain desired high quality materials. Incorporation of the improved materials into device configuration has significantly enhanced the solar cell performance. Using a spectral-splitting, triple-junction configuration, the spectral response of a typical high efficiency device spans from below 350 nm to beyond 950 nm with a peak quantum efficiency exceeding 90%; the triple stack generates a photocurrent of 27 mA/cm2. This paper describes the effect of the improved materials on various solar cell structures, including a 13% active-area, stable triple-junction device.

Dramatically promoted crystallization control of organolead triiodide perovskite film by a homogeneous cap for high efficiency planar-heterojunction solar cells

2016 ◽  
Vol 4 (32) ◽  
pp. 12535-12542 ◽  
Author(s):  
Weidong Zhu ◽  
Chunxiong Bao ◽  
Bihu Lv ◽  
Faming Li ◽  
Yong Yi ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Cell Performance ◽  
High Quality ◽  
Solar Cell Performance ◽  
Heterojunction Solar Cells ◽  
Planar Heterojunction Solar Cells ◽  
Planar Heterojunction

A homogeneous cap-mediated crystallization strategy can be used to realize high-quality organolead triiodide perovskite (OTP) films with greatly enhanced solar cell performance.

The Test System Design of Multi-Junction Solar Cell Spectral Response

2013 ◽  
Vol 706-708 ◽  
pp. 1094-1098
Author(s):  
Fang Bai ◽  
Ke Yuan Cheng ◽  
Shan Li
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Electrical Properties ◽  
Triple Junction ◽  
Spectral Response ◽  
Performance Testing ◽  
Demonstration Program ◽  
Excitation Light ◽  
Solar Cell Performance ◽  
Junction Solar Cell

The main topic is on doing research and testing methods and theories of the triple-junction solar cell and design its electrical performance test platform. Provide a theoretical basis and feasible experimental triple-junction solar cell performance testing. The electrical properties of the electrical properties of solar cells is the main consideration for its use as a power, a very important one is the spectral response curve of the test. Demonstration program and platform for the entire system, the P / N junction between the optical and electrical characteristics of multi-junction solar cells affect each other, related to the key issues, including: monochromatic excitation light source, optical bias, the theory and technology of electrical bias, weak signal detection. Important application prospects based multi-junction solar cells, its theoretical method and test device to become an important and innovative topic.

17.8%-efficient Amorphous Silicon Heterojunction Solar Cells on p-type Silicon Wafers

2006 ◽  
Vol 910 ◽  
Author(s):  
Qi Wang ◽  
Matt P. Page ◽  
Eugene Iwancizko ◽  
Yueqin Xu ◽  
Yanfa Yan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
High Efficiency ◽  
Short Circuit ◽  
Open Circuit ◽  
Layer Growth ◽  
Surface Recombination Velocity ◽  
Back Contact ◽  
P Type

AbstractWe have achieved an independently-confirmed 17.8% conversion efficiency in a 1-cm2, p-type, float-zone silicon (FZ-Si) based heterojunction solar cell. Both the front emitter and back contact are hydrogenated amorphous silicon (a-Si:H) deposited by hot-wire chemical vapor deposition (HWCVD). This is the highest reported efficiency for a HWCVD silicon heterojunction (SHJ) solar cell. Two main improvements lead to our most recent increases in efficiency: 1) the use of textured Si wafers, and 2) the application of a-Si:H heterojunctions on both sides of the cell. Despite the use of textured c-Si to increase the short-circuit current, we were able to maintain the same 0.65 V open-circuit voltage as on flat c-Si. This is achieved by coating a-Si:H conformally on the c-Si surfaces, including covering the tips of the anisotropically-etched pyramids. A brief atomic H treatment before emitter deposition is not necessary on the textured wafers, though it was helpful in the flat wafers. It is essential to high efficiency SHJ solar cells that the emitter grows abruptly as amorphous silicon, instead of as microcrystalline or epitaxial Si. The contact on each side of the cell comprises a thin (< 5 nm) low substrate temperature (~100°C) intrinsic a-Si:H layer, followed by a doped layer. Our intrinsic layers are deposited at 0.3-1.2 nm/s. The doped emitter and back-contact layers were deposited at a higher temperature (>200°C) and grown from PH3/SiH4/H2 and B2H6/SiH4/H2 doping gas mixtures, respectively. This combination of low (intrinsic) and high (doped layer) growth temperatures was optimized by lifetime and surface recombination velocity measurements. Our rapid efficiency advance suggests that HWCVD may have advantages over plasma-enhanced (PE) CVD in fabrication of high-efficiency heterojunction c-Si cells; there is no need for process optimization to avoid plasma damage to the delicate, high-quality, Si wafers.

Annealing Kinetics of Amorphous Silicon Alloy Solar Cells Made at Various Deposition Rates

2001 ◽  
Vol 664 ◽  
Author(s):  
Baojie Yana ◽  
Jeffrey Yanga ◽  
Kenneth Lord ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
High Frequency ◽  
Room Temperature ◽  
Defect Density ◽  
Very High Frequency ◽  
Solar Cell Performance ◽  
Kinetics Of ◽  
Very High

ABSTRACTA systematic study has been made of the annealing kinetics of amorphous silicon (a-Si) alloy solar cells. The cells were deposited at various rates using H2 dilution with radio frequency (RF) and modified very high frequency (MVHF) glow discharge. In order to minimize the effect of annealing during light soaking, the solar cells were degraded under 30 suns at room temperature to quickly reach their saturated states. The samples were then annealed at an elevated temperature. The J-V characteristics were recorded as a function of annealing time. The correlation of solar cell performance and defect density in the intrinsic layer was obtained by computer simulation. Finally, the annealing activation energy distribution (Ea) was deduced by fitting the experimental data to a theoretical model. The results show that the RF low rate solar cell with high H2 dilution has the lowest Ea and the narrowest distribution, while the RF cell with no H2 dilution has the highest Ea and the broadest distribution. The MVHF cell made at 8Å/s withhigh H2 dilution shows a lower Ea and a narrower distribution than the RF cell made at 3 Å/s, despite the higher rate. We conclude that different annealing kinetics plays an important role in determining the stabilized performance of a-Si alloy solar cells.

Growth of Thin μc-Si:H on Intrinsic a-Si:H for Solar Cells Application

1996 ◽  
Vol 452 ◽  
Author(s):  
P. Pemet ◽  
M. Goetz ◽  
H. Keppner ◽  
A. Shah
Keyword(s):  
Stainless Steel ◽  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Solar Cell Performance ◽  
Hydrogenated Silicon ◽  
Boron Doped ◽  
High Efficiency Solar Cells ◽  
Amorphous Substrates ◽  
Interface Treatment

AbstractThe <p> μc-SiC:H / <i> a-Si:H junction can be considered to be a sub-system of a n/i/p solar cell. Optimised performance of this junction can be assumed to be a key feature for obtaining high efficiency solar cells.In this paper the authors present results on the conductivity of boron doped microcrystalline hydrogenated silicon (<p> μc-Si:H) thin films deposited on amorphous substrates (e.g. glass or glass/<i> a-Si:H). It is shown that, without any treatment of the substrate or of the underlying surface, the <p> layers showed a strongly reduced conductivity. This indicates either a bad nucleation or a poor microcrystalline behaviour. By using an appropriate surface treatment of the substrate, a gain in photoconductivity of about three orders of magnitude could be obtained (σ > 3 S/cm at a layer thickness of 400Å). We conclude from this, that for thin <p> type μc-Si:H layers the nucleation conditions are essential for obtaining best electric properties of the film w.r.t. solar cell performance.Based on these results, interface treatment was successfully implemented in n/i/p solar cells deposited on TCO coated glass and stainless steel. The results of these experiments are also presented.

Metamorphic GaInP-GaInAs Layers for Photovoltaic Applications

2004 ◽  
Vol 836 ◽  
Author(s):  
A. W. Bett ◽  
C. Baur ◽  
F. Dimroth ◽  
J. Schöne
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Triple Junction ◽  
Cell Structure ◽  
X Ray Diffraction ◽  
Solar Cell Performance ◽  
Transmission Electron ◽  
Layer Structures ◽  
Buffer Material ◽  
Metal Organic

ABSTRACTGaxIn1−xAs and GayIn1−yP layers were grown lattice mismatched to GaAs and Ge by low-pressure metal organic vapor phase epitaxy (LP-MOPVE). These materials are very promising for further increasing the efficiency of monolithic triple-junction solar cells. Different buffer layer structures were realized. Transmission electron microscopy and x-ray diffraction analysis were used to characterize the quality of the crystal. Both linear and step-graded buffers in GaxIn1−xAs were successfully used under an active solar cell structure. GayIn1−yP as buffer material showed a worse performance. Excellent solar cell performance was achieved for lattice mismatched single-, dual- and triple-junction solar cells.

A high efficiency solution processed polymer inverted triple-junction solar cell exhibiting a power conversion efficiency of 11.83%

2015 ◽  
Vol 8 (1) ◽  
pp. 303-316 ◽  
Author(s):  
Abd. Rashid bin Mohd Yusoff ◽  
Dongcheon Kim ◽  
Hyeong Pil Kim ◽  
Fabio Kurt Shneider ◽  
Wilson Jose da Silva ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Triple Junction ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Power Conversion ◽  
Open Circuit ◽  
Tandem Solar Cells

We propose that 1 + 1 + 1 triple-junction solar cells can provide an increased efficiency, as well as a higher open circuit voltage, compared to tandem solar cells.

Amorphous Silicon Solar Cell Techniques for High Temperature and/or Reactive Deposition Conditions

1999 ◽  
Vol 557 ◽  
Author(s):  
M. Kanbe ◽  
T. Komaru ◽  
K. Fukutani ◽  
T. Kamiya ◽  
C.M. Fortmann ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Silicon Solar Cell ◽  
Hydrogen Diffusion ◽  
Hydrogen Reduction ◽  
Poor Performance ◽  
N Deposition ◽  
Solar Cell Performance ◽  
Amorphous Silicon Solar Cell

AbstractSeveral promising new methods for amorphous silicon solar cell preparation involve high substrate temperatures and/or very reactive atmospheres. When incorporated into solar cells, the performance of these layers has often been less than expected due to enhanced diffusion and/or chemical reactions. This poor performance results from the harsh deposition environments. Deleterious effects include darken of TCO coated glass substrates due to hydrogen diffusion to and hydrogen reduction at the TCO interface when solar cells are prepared in the p-i-n deposition sequence. Alternatively, the deposition of TCO layers onto amorphous layers also involves rather harsh oxidizing conditions that have a deleterious effect on the top most amorphous silicon-based p-layers. Strategic use of blocking layers results in remarkably improved solar cell performance. A thin Cr layer (probably becoming Cr2O3) shows ability to improve the performance of both n-ip and p-i-n solar cells by inhibiting both O and H diffusion.

High Efficiency Thin Film Silicon Solar Cells

2013 ◽  
Vol 750-752 ◽  
pp. 970-973
Author(s):  
Chun Rong Xue ◽  
Xia Yun Sun
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Amorphous Silicon ◽  
Triple Junction ◽  
High Efficiency ◽  
Silicon Solar Cells ◽  
Cell Efficiency ◽  
High Efficiency Solar Cells ◽  
Alternative Material ◽  
Staebler Wronski Effect

High-efficiency solar cells based on amorphous silicon technology are designed. Multi-junction amorphous silicon solar cells are discussed, how these are made and how their performance can be understood and optimized. Although significant amount of work has been carried out in the last twenty-five years, the Staebler-Wronski effect has limited the development of a-Si:H solar cells. As an alternative material, nc-Si:H has attracted remarkable attention. Taking advantage of a lower degradation in nc-Si:H than a-Si:H and a-SiGe:H alloys, the light induced degradation in triple junction structures has been minimized by designing a bottom-cell-limited current mismatching, and obtained a stable active-area cell efficiency. All this has been investigated in this paper.

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