Solar cell degradation under open circuit condition in out-doors-in desert region

AbstractNew types of transparent conductive oxides with low indices of refraction have been developed for use in optical stacks for the amorphous silicon (a-Si) solar cell and other thin film applications. The alloys are ZnO based with Si and MgF added to reduce the index of the materials through the creation of SiO2 or MgF2, with n=1.3-1.4, or the addition of voids in the materials. Alloys with 12-14% Si or Mg have indices of refraction at λ=800nm between 1.6 and 1.7. These materials are presently being used in optical stacks to enhance light scattering by Al/multi-layer/ZnO back reflectors in a-Si based solar cells to increase light absorption in the semiconductor layers and increase open circuit currents and boost device efficiencies. In contrast to Ag/ZnO back reflectors which have long term stability issues due to electromigration of Ag, these Al based back reflectors should be stable and usable in manufactured PV products. In this manuscript, structural properties for the materials will be reported as well as the performance of solar cell devices made using these new types of materials.

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

Energies ◽

10.3390/en14030592 ◽

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.

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CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽

10.3390/en14061684 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1684

Author(s):

Alessandro Romeo ◽

Elisa Artegiani

Keyword(s):

Thin Film ◽

Solar Cells ◽

Solar Cell ◽

Short Circuit ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Early Years ◽

Solar Cell Efficiency ◽

Cell Efficiency

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.

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

Crystals ◽

10.3390/cryst11070726 ◽

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.

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Enhancement of the performance of CdS/CdTe heterojunction solar cell using TiO2/ZnO bi-layer ARC and V2O5 BSF layers: A simulation approach

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200213 ◽

2020 ◽

Vol 92 (2) ◽

pp. 20901

Author(s):

Abdul Kuddus ◽

Md. Ferdous Rahman ◽

Jaker Hossain ◽

Abu Bakar Md. Ismail

Keyword(s):

Solar Cell ◽

Short Circuit ◽

Photovoltaic Performance ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Heterojunction Solar Cell ◽

Back Surface ◽

Heterojunction Solar Cells

This article presents the role of Bi-layer anti-reflection coating (ARC) of TiO2/ZnO and back surface field (BSF) of V2O5 for improving the photovoltaic performance of Cadmium Sulfide (CdS) and Cadmium Telluride (CdTe) based heterojunction solar cells (HJSCs). The simulation was performed at different concentrations, thickness, defect densities of each active materials and working temperatures to optimize the most excellent structure and working conditions for achieving the highest cell performance using obtained optical and electrical parameters value from the experimental investigation on spin-coated CdS, CdTe, ZnO, TiO2 and V2O5 thin films deposited on the glass substrate. The simulation results reveal that the designed CdS/CdTe based heterojunction cell offers the highest efficiency, η of ∼25% with an enhanced open-circuit voltage, Voc of 0.811 V, short circuit current density, Jsc of 38.51 mA cm−2, fill factor, FF of 80% with bi-layer ARC and BSF. Moreover, it appears that the TiO2/ZnO bi-layer ARC, as well as ETL and V2O5 as BSF, could be highly promising materials of choice for CdS/CdTe based heterojunction solar cell.

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

MRS Proceedings ◽

10.1557/proc-0910-a26-05 ◽

2006 ◽

Vol 910 ◽

Cited By ~ 2

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.

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A Liquid Junction Photoelectrochemical Solar Cell Based on p-Type MeNH3PbI3 Perovskite with 1.05 V Open-Circuit Photovoltage

Journal of the American Chemical Society ◽

10.1021/jacs.5b09758 ◽

2015 ◽

Vol 137 (46) ◽

pp. 14758-14764 ◽

Cited By ~ 30

Author(s):

Hsien-Yi Hsu ◽

Li Ji ◽

Hyun S. Ahn ◽

Ji Zhao ◽

Edward T. Yu ◽

...

Keyword(s):

Solar Cell ◽

Open Circuit ◽

Liquid Junction ◽

Photoelectrochemical Solar Cell ◽

P Type ◽

Open Circuit Photovoltage

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Photoanode characteristics of dye-sensitized solar cell containing TiO2 layers with different crystalline orientations

Journal of Materials Research ◽

10.1557/jmr.2009.0157 ◽

2009 ◽

Vol 24 (4) ◽

pp. 1417-1421 ◽

Cited By ~ 6

Author(s):

Mamiko Kawakita ◽

Jin Kawakita ◽

Tetsuo Uchikoshi ◽

Yoshio Sakka

Keyword(s):

Solar Cell ◽

Electrochemical Reaction ◽

Dye Adsorption ◽

Open Circuit ◽

Dye Sensitized Solar Cell ◽

Photoelectric Conversion Efficiency ◽

Electrochemical Characteristics ◽

Cathodic Reaction ◽

Photoelectric Conversion ◽

Dye Sensitized

The influence of the crystalline orientation of the TiO2 photoanode on the photo-electrochemical characteristics was investigated to reveal the primary factors responsible for improving the photoelectric conversion efficiency of a dye-sensitized solar cell. It was observed that the photocurrent depended on the plane orientation, whereas the dependence of the photopotential on the open circuit was almost constant. The rate of the photoanodic reaction was attributed to the dye adsorption, depending on the surface energy of each oriented plane of the TiO2. The cathodic reaction on TiO2 during open circuit is likely to determine the rate of the entire electrochemical reaction.

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