11.0% Stable Efficiency on Large Area, Encapsulated a-Si:H and a-SiGe:H based Multijunction Solar Cells Using HF Technology

2011 ◽  
Vol 1321 ◽  
Author(s):  
A. Banerjee ◽  
D. Beglau ◽  
T. Su ◽  
G. Pietka ◽  
G. Yue ◽  
...  
Keyword(s):  
Solar Cells ◽  
Triple Junction ◽  
Gas Flow ◽  
High Efficiency ◽  
Open Circuit ◽  
Large Area ◽  
Multijunction Solar Cells ◽  
Double Junction ◽  
Junction Structure ◽  
Cell Thickness

ABSTRACTWe report on the investigation of large area a-Si:H/a-SiGe:H double-junction and a-Si:H/a-SiGe:H/a-SiGe:H triple-junction solar cells prepared by our proprietary High Frequency (HF) glow discharge technique. For investigative purposes, we initially used the simpler double-junction structure. We studied the effect of: (1) Ge content, (2) cell thickness, and (3) SiH4 and GeH4 gas flow on the light-induced degradation of the solar cells. Our results show that the double-junction cells with different Ge concentration have open-circuit voltage (Voc) in the range of 1.62-1.75 V. Voc exhibits a flat plateau in the range of 1.65-1.72 V for both initial and stabilized states. The light-induced degradation for cells in this range of Voc is insensitive to the Ge content. In terms of thickness dependence of the intrinsic layers, we found that the initial efficiency increases with cell thickness in the thickness range 2000-4000 Å. However, light-induced degradation increases with increasing thickness. Consequently, the stabilized efficiency is invariant with cell thickness in the thickness range studied. The results of SiH4 and GeH4 gas flow on cell characteristics demonstrate that the deposition rate decreases by only 20% when the active gas flow is reduced to 0.25 times standard flow. The initial and stabilized efficiencies are similar. The information gleaned from the study was used to fabricate high efficiency, large area (~464 cm2) double- and triple-junction solar cells. The highest stable efficiency, as measured by NREL, was 9.8% and 11.0% for the double- and triple-junction structures, respectively.

Amorphous Silicon Alloy Solar Cells Near the Threshold of Amorphous-to-Microcrystalline Transition

2000 ◽  
Vol 609 ◽  
Author(s):  
Jeffrey Yang ◽  
Kenneth Lord ◽  
Subhendu Guha ◽  
S.R. Ovshinsky
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Area Efficiency ◽  
Junction Device ◽  
Tandem Structure ◽  
Double Junction ◽  
Junction Structure

ABSTRACTA systematic study has been made of amorphous silicon (a-Si) alloy solar cells using various hydrogen dilutions during the growth of the intrinsic (i) layer. We find that the open-circuit voltage (Voc) of the cells increases as the dilution increases; it then reaches a maximum before it decreases dramatically. This sudden drop in Voc is attributed to the transition from amorphous silicon to microcrystalline inclusions in the i layer. We study i-layer thicknesses ranging from 1000 Å to 5000 Å and find that the transition occurs in all thicknesses investigated. Based on this study, a-Si alloy p i n solar cells suitable for use in the top cell of a high efficiency triple-junction structure are made. By selecting an appropriate dilution, cells with Voc greater than 1 V can be achieved readily. Solar cells made near the threshold not only exhibit higher initial characteristics but also better stability against light soaking. We have compared top cells made near the threshold with our previous best data, and found that both the initial and stable efficiencies are superior for the near-threshold cells. For an a-Si/a-Si double-junction device, a Voc value exceeding 2 V has been obtained using thin component cells. Thicker component cells give rise to an initial active-area efficiency of 11.9% for this tandem structure.

scholarly journals Modeling and Optimization of Advanced Single- and Multijunction Solar Cells Based on Thin-Film a-Si:H/SiGe Heterostructure

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Abdolnabi Kosarian ◽  
Peyman Jelodarian
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Thin Film Solar Cell ◽  
Open Circuit ◽  
Single Junction ◽  
Multijunction Solar Cells ◽  
Double Junction ◽  
Thick Absorber ◽  
Junction Structure

In amorphous thin-film p-i-n solar cell, a thick absorber layer can absorb more light to generate carriers. On the other hand, a thin i-layer cannot absorb enough light. Thickness of the i-layer is a key parameter that can limit the performance of solar cell. Introducing Ge atoms to the Si lattice in Si-based solar cells is an effective approach in improving their characteristics. Especially, current density of the cell can be enhanced without deteriorating its open circuit voltage, due to the modulation of material band-gap and the formation of a heterostructure. This work presents a novel numerical evaluation and optimization of an amorphous silicon double-junction structure thin-film solar cell (a-SiGe:H/a-Si:H) and focuses on optimization of a-SiGe:H mid-gap single-junction solar cell based on the optimization of the Ge content in the film, thickness of i-layer, p-layer and doping concentration of p-layer in a (p-layer a-Si:H/i-layer a-SiGe:H/n-layer a-Si:H) single-junction thin-film solar cell. Optimization shows that for an appropriate Ge concentration, the efficiency of a-Si:H/a-SiGe solar cell is improved by about 6.5% compared with the traditional a-Si:H solar cells.

Large-Area Hydrogenated Amorphous and Microcrystalline Silicon Double-Junction Solar Cells

2004 ◽  
Vol 808 ◽  
Author(s):  
Baojie Yan ◽  
Guozhen Yue ◽  
Arindam Banerjee ◽  
Jeffrey Yang ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Deposition Time ◽  
High Rate ◽  
Microcrystalline Silicon ◽  
Large Area ◽  
Area Efficiency ◽  
Rf Glow Discharge ◽  
Double Junction ◽  
Junction Structure ◽  
Hydrogenated Amorphous

ABSTRACTHydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon ( c-Si:H) double-junction solar cells were deposited on a large-area substrate using a RF glow discharge technique at various rates. The thickness uniformity for both a-Si:H and c-Si:H is well within ± 10% and the reproducibility is very good. Preliminary results from the large-area a-Si:H/m c-Si:H double-junction structures show an initial aperture-area efficiency of 11.8% and 11.3%, respectively, for 45 cm2 and 461 cm2 size un-encapsulated solar cells. The 11.3% cell became 10.6% after encapsulation and stabilized at 9.5% after prolonged light soaking under 100 mW/cm2 of white light at 50°C. High rate deposition of the c-Si:H layer in the bottom cell was made using the high-pressure approach. An initial active-area (0.25 cm2) efficiency of 11.3% was achieved using an a-Si:H/m c-Si:H double-junction structure with 50 minutes of c-Si:H deposition time.

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.

High efficiency amorphous and nanocrystalline silicon based multi-junction solar cells deposited at high rates on textured Ag/ZnO back reflectors

2009 ◽  
Vol 1153 ◽  
Author(s):  
Guozhen Yue ◽  
Laura Sivec ◽  
Baojie Yan ◽  
Jeff Yang ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Triple Junction ◽  
High Efficiency ◽  
Nanocrystalline Silicon ◽  
Open Circuit ◽  
Very High Frequency ◽  
Solar Cell Performance ◽  
Single Junction ◽  
Back Reflectors ◽  
Back Reflector

AbstractWe report our recent progress on nc-Si:H single-junction and a-Si:H/nc-Si:H/nc-Si:H triple-junction cells made by a modified very-high-frequency (MVHF) technique at deposition rates of 10-15 Å/s. First, we studied the effect of substrate texture on the nc-Si:H single-junction solar cell performance. We found that nc-Si:H single-junction cells made on bare stainless steel (SS) have a good fill factor (FF) of ˜0.73, while it decreased to ˜0.65 when the cells were deposited on textured Ag/ZnO back reflectors. The open-circuit voltage (Voc) also decreased. We used dark current-voltage (J-V), Raman, and X-ray diffraction (XRD) measurements to characterize the material properties. The dark J-V measurement showed that the reverse saturated current was increased by a factor of ˜30 when a textured Ag/ZnO back reflector was used. Raman results revealed that the nc-Si:H intrinsic layers in the two solar cells have similar crystallinity. However, they showed a different crystallographic orientation as indicated in XRD patterns. The material grown on Ag/ZnO has more random orientation than that on SS. These experimental results suggested that the deterioration of FF in nc-Si:H solar cells on textured Ag/ZnO was caused by poor nc-Si:H quality. Based on this study, we have improved our Ag/ZnO back reflector and the quality of nc-Si:H component cells and achieved an initial and stable active-area efficiencies of 13.4% and 12.1%, respectively, in an a-Si:H/nc-Si:H/nc-Si:H triple-junction cell.

High Efficiency Hydrogenated Nanocrystalline Silicon Solar Cells Deposited at High Rates

2010 ◽  
Vol 1245 ◽  
Author(s):  
Guozhen Yue ◽  
Laura Sivec ◽  
Baojie Yan ◽  
Jeff Yang ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Triple Junction ◽  
High Efficiency ◽  
Nanocrystalline Silicon ◽  
Active Area ◽  
Very High Frequency ◽  
Area Efficiency ◽  
Hydrogen Dilution ◽  
Back Reflectors ◽  
Junction Structure

AbstractWe report recent progress on hydrogenated nanocrystalline silicon (nc-Si:H) solar cells prepared at different deposition rates. The nc-Si:H intrinsic layer was deposited, using a modified very high frequency (MVHF) glow discharge technique, on Ag/ZnO back reflectors (BRs). The nc-Si:H material quality, especially the evolution of the nanocrystallites, was optimized using hydrogen dilution profiling. First, an initial active-area efficiency of 10.2% was achieved in a nc-Si:H single-junction cell deposited at ~5 Å/s. Using the improved nc-Si:H cell, we obtained 14.5% initial and 13.5% stable active-area efficiencies in an a-Si:H/nc-Si:H/nc-Si:H triple-junction structure. Second, we achieved a stabilized total-area efficiency of 12.5% using the same triple-junction structure but with nc-Si:H deposited at ~10 Å/s; the efficiency was measured at the National Renewable Energy Laboratory (NREL). Third, we developed a recipe using a shorter deposition time and obtained initial 13.0% and stable 12.7% active-area efficiencies for the same triple-junction design.

scholarly journals Аномалии в фотовольтаических характеристиках многопереходных солнечных элементов при сверхвысоких концентрациях солнечного излучения

2019 ◽  
Vol 45 (21) ◽  
pp. 37
Author(s):  
М.А. Минтаиров ◽  
В.В. Евстропов ◽  
С.А. Минтаиров ◽  
М.З. Шварц ◽  
Н.А. Калюжный
Keyword(s):  
Solar Cells ◽  
Triple Junction ◽  
Open Circuit Voltage ◽  
Photovoltaic Effect ◽  
Open Circuit ◽  
Tunnel Diode ◽  
Double Junction ◽  
High Concentrations ◽  
Photovoltaic Characteristics ◽  
Iv Curves

An anomaly arising in photovoltaic characteristics at ultra-high concentrations (more than 2000 suns) in triple-junction GaInP/GaAs/Ge and in the double-junction GaInP/GaAs solar cells has been studied. The light IV-curves at different sun concentrations and dependence of open circuit voltage on photogenerated current have been analyzed. It is shown that the anomaly is caused by the photovoltaic effect source, counteracting the subcells. The reason for this effect – absorption of photons intended for GaAs subcell in the tunnel diode located between GaInP and GaAs sub-cells.

Critical Materials Parameters for the Development of Amorphous Silicon Alloys

1985 ◽  
Vol 49 ◽  
Author(s):  
Stanford R. Ovshinsky ◽  
David Adler
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
High Efficiency ◽  
Active Material ◽  
Dual Band ◽  
Large Area ◽  
Silicon Alloys ◽  
Viable Cells ◽  
Multijunction Solar Cells ◽  
Critical Materials

AbstractThe desired properties of solar cells are discussed, and a relative figure of merit for the comparison of cells fabricated using different technologies is described. The advantages of utilizing amorphous silicon alloys as the active material in solar cells are enumerated. Selected materials properties of these alloys are described and the physics of their electronic structure is discussed in detail. The necessary steps for achieving commercially viable cells based on amorphous silicon alloys are listed, and it is demonstrated how each of them has been achieved using a technology that incorporates fluorine throughout the entire process. The chemical and physical basis for the superiority of fluorinated material is presented in detail. Continuous web large-area high-efficiency multijunction solar cells are in production. Dual band gap multijunction cells have been tested under continuous air mass 1 exposure for over 2000 hours and show essentially no degradation. Some recent results are presented.

scholarly journals Numerical Simulation Analysis of Ag Crystallite Effects on Interface of Front Metal and Silicon in the PERC Solar Cell

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 592
Author(s):  
Myeong Sang Jeong ◽  
Yonghwan Lee ◽  
Ka-Hyun Kim ◽  
Sungjin Choi ◽  
Min Gu Kang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Surface Recombination ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Metal Interface ◽  
Ag Crystallites ◽  
Recombination Velocity

In the fabrication of crystalline silicon solar cells, the contact properties between the front metal electrode and silicon are one of the most important parameters for achieving high-efficiency, as it is an integral element in the formation of solar cell electrodes. This entails an increase in the surface recombination velocity and a drop in the open-circuit voltage of the solar cell; hence, controlling the recombination velocity at the metal-silicon interface becomes a critical factor in the process. In this study, the distribution of Ag crystallites formed on the silicon-metal interface, the surface recombination velocity in the silicon-metal interface and the resulting changes in the performance of the Passivated Emitter and Rear Contact (PERC) solar cells were analyzed by controlling the firing temperature. The Ag crystallite distribution gradually increased corresponding to a firing temperature increase from 850 ∘C to 950 ∘C. The surface recombination velocity at the silicon-metal interface increased from 353 to 599 cm/s and the open-circuit voltage of the PERC solar cell decreased from 659.7 to 647 mV. Technology Computer-Aided Design (TCAD) simulation was used for detailed analysis on the effect of the surface recombination velocity at the silicon-metal interface on the PERC solar cell performance. Simulations showed that the increase in the distribution of Ag crystallites and surface recombination velocity at the silicon-metal interface played an important role in the decrease of open-circuit voltage of the PERC solar cell at temperatures of 850–900 ∘C, whereas the damage caused by the emitter over fire was determined as the main cause of the voltage drop at 950 ∘C. These results are expected to serve as a steppingstone for further research on improvement in the silicon-metal interface properties of silicon-based solar cells and investigation on high-efficiency solar cells.

scholarly journals GaInP/GaAs/poly-Si Multi-Junction Solar Cells by in Metal Balls Bonding

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 726
Author(s):  
Ray-Hua Horng ◽  
Yu-Cheng Kao ◽  
Apoorva Sood ◽  
Po-Liang Liu ◽  
Wei-Cheng Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Low Temperature ◽  
Triple Junction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Metal Line ◽  
Solar Simulator ◽  
Junction Solar Cell

In this study, a mechanical stacking technique has been used to bond together the GaInP/GaAs and poly-silicon (Si) solar wafers. A GaInP/GaAs/poly-Si triple-junction solar cell has mechanically stacked using a low-temperature bonding process which involves micro metal In balls on a metal line using a high-optical-transmission spin-coated glue material. Current–voltage measurements of the GaInP/GaAs/poly-Si triple-junction solar cells have carried out at room temperature both in the dark and under 1 sun with 100 mW/cm2 power density using a solar simulator. The GaInP/GaAs/poly-Si triple-junction solar cell has reached an efficiency of 24.5% with an open-circuit voltage of 2.68 V, a short-circuit current density of 12.39 mA/cm2, and a fill-factor of 73.8%. This study demonstrates a great potential for the low-temperature micro-metal-ball mechanical stacking technique to achieve high conversion efficiency for solar cells with three or more junctions.

Sign in / Sign up

Export Citation Format

Share Document