Development of the Very thin Microcrystalline N-Layer and its Application to the Stacked Solar Cell

1989 ◽  
Vol 164 ◽  
Author(s):  
F. Nakabeppu ◽  
T. Ishimura ◽  
K. Kumagai ◽  
K. Fukui
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Light Absorption ◽  
Preparation Method ◽  
Conductivity Measurement ◽  
Absorption Loss ◽  
Microcrystalline Silicon ◽  
Ar Gas

AbstractIn order to improve the efficiency of the amorphous silicon stacked solar cells, we have developed the preparation method of highly conductive very thin microcrystalline silicon n-layers. We have found that the addition of a small amount of Ar gas to deposition gases is effective to make microcrystallite size small. The obtained thin films were characterized by conductivity measurement, R-HEED observation and TEM observation.This newly developed thin microcrystalline n-layers have been applied to the stacked solar cells. Increase of Jsc by 5-6% has been achieved because of the reduction of light absorption loss in n-layer without decrease of Voc and FF.

scholarly journals Material and solar cell research in high efficiency micromorph tandem solar cell

2015 ◽  
Vol 37 ◽  
pp. 434 ◽  
Author(s):  
Razagh Hafezi ◽  
Soroush Karimi ◽  
Sharie Jamalzae ◽  
Masoud Jabbari
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
High Efficiency ◽  
Crystalline Silicon ◽  
Chemical Vapour ◽  
Microcrystalline Silicon ◽  
Tandem Solar Cells ◽  
Bottom Cell

“Micromorph” tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchâtel, based on the VHF-GD (very high frequency glow discharge) deposition method. The key element of the micromorph cell is the hydrogenated microcrystalline silicon bottom cell that opens new perspectives for low-temperature thin-film crystalline silicon technology. This paper describes the use, within p–i–n- and n–i–p-type solar cells, of hydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon (_c-Si:H) thin films (layers), both deposited at low temperatures (200_C) by plasma-assisted chemical vapour deposition (PECVD), from a mixture of silane and hydrogen. Optical and electrical properties of the i-layers are described. Finally, present performances and future perspectives for a high efficiency ‘micromorph’ (mc-Si:Hya-Si:H) tandem solar cells are discussed.

scholarly journals N-I-P Micromorph Solar Cells on Aluminium Substrates

1996 ◽  
Vol 452 ◽  
Author(s):  
M. Goetz ◽  
P. Torres ◽  
P. Pernet ◽  
J. Meier ◽  
D. Fischer ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Spectral Response ◽  
Single Layer ◽  
Antireflection Coating ◽  
Microcrystalline Silicon ◽  
Single Junction ◽  
Junction Solar Cell ◽  
Single Junction Solar Cell

AbstractThe first successful deposition of ‘micromorph’ silicon tandem solar cells of the n-i-p-n-i-p configuration is reported. In order to implement the ‘micromorph’ solar cell concept, four key elements had to be prepared: First, the deposition of mid-gap, intrinsic microcrystalline silicon (μc-Si:H) by the 'gas purifier method', second, the amorphous silicon (a-Si:H) n-i-p single junction solar cell, third, the microcrystalline silicon n-i-p single junction solar cell and fourth, the ability of depositing on aluminium sheet substrates.All the solar cells presented have been deposited on flat aluminium sheets, using a single layer antireflection coating to couple the light into the cell. It is shown, that this antireflection concept- together with a flat substrate- holds for amorphous single junction solar cells, but it reaches its limit with the extended range of spectral response of the ‘micromorph’ cell.The best initial efficiencies for each category of n-i-p cells on flat substrates were: 8.7% for the amorphous silicon single junction cell, 4.9% for the microcrystalline silicon single junction cell and 9.25% for the ‘micromorph’ tandem cell.

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.

scholarly journals Grown Low-Temperature Microcrystalline Silicon Thin Film by VHF PECVD for Thin Films Solar Cell

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Shanglong Peng ◽  
Desheng Wang ◽  
Fuhua Yang ◽  
Zhanguo Wang ◽  
Fei Ma
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
High Growth ◽  
Microcrystalline Silicon ◽  
Silicon Thin Film ◽  
Very High Frequency ◽  
Silicon Thin Films

Hydrogenated microcrystalline silicon thin films can be used to fabricate stable thin film solar cell, which were deposited by very high frequency plasma-enhanced chemical vapor deposition at low temperatures (~200°C). It has been found that the obtained film presented excellent structural and electrical properties, such as high growth rate and good crystallinity. With the decreasing of silane concentration, the optical gap and the dark conductivity increased, whereas the activation energy decreased. A reasonable explanation was presented to elucidate these phenomena. In addition, we fabricated p-i-n structure solar cells using the optimum microcrystalline silicon thin films, and preliminary efficiency of 4.6% was obtained for 1 μm thick microcrystalline silicon thin film solar cells with open-circuits voltage of 0.773 V and short-circuits current density of 12.28 mA/cm2. Future scope for performance improvement lies mainly in further increasing the short-circuit current.

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.

scholarly journals Description of a Naphthoquinonic Crystal Produced by the Fungus Scytalidium cuboideum

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1905 ◽  
Author(s):  
Sarath Gutierrez ◽  
Kenya Hazell ◽  
John Simonsen ◽  
Seri Robinson
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Nuclear Magnetic Resonance ◽  
Solar Cells ◽  
Solar Cell ◽  
Material Science ◽  
Rare Occurrence ◽  
Crystalline Materials ◽  
Art Form ◽  
Pink Pigment

Intarsia was an art form popular between the 15th–18th centuries that used wood pigmented by spalting fungi to create detailed landscapes, portraits, and other imagery. These fungi are still used today in art but are also finding relevance in material science as elements of solar cells, textile dyes, and paint colorants. Here we show that the spalting fungus Scytalidium cuboideum (Sacc. and Ellis) Sigler and Kang produces a red/pink pigment that forms two distinct colors of crystals (red and orange)—a very rare occurrence. In addition, a second structure of the crystal is proved through nuclear magnetic resonance (NMR). This is only the second instance of a stable, naphthoquinone crystal produced by a fungus. Its discovery is particularly valuable for solar cell development, as crystalline materials have a higher electrical conductivity. Other fungi in this order have shown strong potential as thin films for solar cells.

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.

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.

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