Multi-Walled Carbon Nanotube-Assisted Encapsulation Approach for Stable Perovskite Solar Cells

Perovskite solar cells (PSCs) are regarded as the next-generation thin-film energy harvester, owing to their high performance. However, there is a lack of studies on their encapsulation technology, which is critical for resolving their shortcomings, such as their degradation by oxygen and moisture. It is determined that the moisture intrusion and the heat trapped within the encapsulating cover glass of PSCs influenced the operating stability of the devices. Therefore, we improved the moisture and oxygen barrier ability and heat releasing capability in the passivation of PSCs by adding multi-walled carbon nanotubes to the epoxy resin used for encapsulation. The 0.5 wt% of carbon nanotube-added resin-based encapsulated PSCs exhibited a more stable operation with a ca. 30% efficiency decrease compared to the ca. 63% decrease in the reference devices over one week under continuous operation. Specifically, the short-circuit current density and the fill factor, which are affected by moisture and oxygen-driven degradation, as well as the open-circuit voltage, which is affected by thermal damage, were higher for the multi-walled carbon nanotube-added encapsulated devices than the control devices, after the stability test.

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Iodide management in formamidinium-lead-halide–based perovskite layers for efficient solar cells

Science ◽

10.1126/science.aan2301 ◽

2017 ◽

Vol 356 (6345) ◽

pp. 1376-1379 ◽

Cited By ~ 3378

Author(s):

Woon Seok Yang ◽

Byung-Wook Park ◽

Eui Hyuk Jung ◽

Nam Joong Jeon ◽

Young Chan Kim ◽

...

Keyword(s):

Solar Cells ◽

High Performance ◽

Deep Level ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Small Cells ◽

Iodide Ions

The formation of a dense and uniform thin layer on the substrates is crucial for the fabrication of high-performance perovskite solar cells (PSCs) containing formamidinium with multiple cations and mixed halide anions. The concentration of defect states, which reduce a cell’s performance by decreasing the open-circuit voltage and short-circuit current density, needs to be as low as possible. We show that the introduction of additional iodide ions into the organic cation solution, which are used to form the perovskite layers through an intramolecular exchanging process, decreases the concentration of deep-level defects. The defect-engineered thin perovskite layers enable the fabrication of PSCs with a certified power conversion efficiency of 22.1% in small cells and 19.7% in 1-square-centimeter cells.

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Improving the Morphology of the Perovskite Absorber Layer in Hybrid Organic/Inorganic Halide Perovskite MAPbI3 Solar Cells

Journal of Solar Energy ◽

10.1155/2017/8549847 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

I. J. Ogundana ◽

S. Y. Foo

Keyword(s):

Thin Film ◽

Solar Cells ◽

High Performance ◽

Short Circuit ◽

Photovoltaic Performance ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Perovskite Layer ◽

Large Variability

Recently, perovskite solar cells have attracted tremendous attention due to their excellent power conversion efficiency, low cost, simple fabrications, and high photovoltaic performance. Furthermore, the perovskite solar cells are lightweight and possess thin film and semitransparency. However, the nonuniformity in perovskite layer constitutes a major setback to the operation mechanism, performance, reproducibility, and degradation of perovskite solar cells. Therefore, one of the main challenges in planar perovskite devices is the fabrication of high quality films with controlled morphology and least amount of pin-holes for high performance thin film perovskite devices. The poor reproducibility in perovskite solar cells hinders the accurate fabrication of practical devices for use in real world applications, and this is primarily as a result of the inability to control the morphology of perovskites, leading to large variability in the characteristics of perovskite solar cells. Hence, the focus of research in perovskites has been mostly geared towards improving the morphology and crystallization of perovskite absorber by selecting the optimal annealing condition considering the effect of humidity. Here we report a controlled ambient condition that is necessary to grow uniform perovskite crystals. A best PCE of 7.5% was achieved along with a short-circuit current density of 15.2 mA/cm2, an open-circuit voltage of 0.81 V, and a fill factor of 0.612 from the perovskite solar cell prepared under 60% relative humidity.

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Optical Simulation and Investigation of the Effect of Hysteresis on the Perovskite Solar Cells

NANO ◽

10.1142/s1793292019501273 ◽

2019 ◽

Vol 14 (10) ◽

pp. 1950127 ◽

Cited By ~ 4

Author(s):

Farhad Jahantigh ◽

S. M. Bagher Ghorashi

Keyword(s):

Grain Size ◽

Solar Cells ◽

Open Circuit Voltage ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Hole Transport ◽

Transport Layer ◽

Hole Transport Layer

Perovskite solar cells have recently been considered to be an auspicious candidate for the advancement of future photovoltaic research. A power conversion efficiency (PCE) as high as 22% has been reported to be reached, which can be obtained through an inexpensive and high-throughput solution process. Modeling and simulation of these cells can provide deep insights into their fundamental mechanism of performance. In this paper, two different perovskite solar cells are designed by using COMSOL Multiphysics to optimize the thickness of each layer and the overall thickness of the cell. Electric potential, electron and hole concentrations, generation rate, open-circuit voltage, short-circuit current and the output power were calculated. Finally, PCEs of 20.7% and 26.1% were predicted. Afterwards, according to the simulation results, the role of the hole transport layer (HTL) was investigated and the optimum thickness of the perovskite was measured to be 200[Formula: see text]nm for both cells. Therefore, the spin coating settings are selected so that a coating with this thickness for cell 1 is deposited. In order to compare the performance of HTM layer, solar cells with a Spiro-OMeTAD HTM and without the HTM layer in their structure were fabricated. According to the obtained photovoltaic properties, the solar cell made with Spiro-OMeTAD has a more favorable open-circuit voltage ([Formula: see text]), short-circuit current density ([Formula: see text]), fill factor (FF) and PCE compared to the cell without the HTM layer. Also, hysteresis depends strongly on the perovskite grain size, because large average grain size will lead to an increase in the grain’s contact surface area and a decrease in the density of grain boundaries. Finally, according to the results, it was concluded that, in the presence of a hole transport layer, ion transfer was better and ion accumulation was less intense, and therefore, the hysteresis decreases.

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Fabrication and Characterization of CH3NH3PbI3 Perovskite Solar Cells Added with Polysilanes

International Journal of Photoenergy ◽

10.1155/2018/8654963 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 9

Author(s):

Takeo Oku ◽

Junya Nomura ◽

Atsushi Suzuki ◽

Hiroki Tanaka ◽

Sakiko Fukunishi ◽

...

Keyword(s):

Solar Cells ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Interfacial Structure ◽

Perovskite Layer ◽

Photovoltaic Properties ◽

Coating Method

Effects of polysilane additions on CH3NH3PbI3 perovskite solar cells were investigated. Photovoltaic cells were fabricated by a spin-coating method using perovskite precursor solutions with polymethyl phenylsilane, polyphenylsilane, or decaphenyl cyclopentasilane (DPPS), and the microstructures were examined by X-ray diffraction and optical microscopy. Open-circuit voltages were increased by introducing these polysilanes, and short-circuit current density was increased by the DPPS addition, which resulted in the improvement of the photoconversion efficiencies to 10.46%. The incident photon-to-current conversion efficiencies were also increased in the range of 400~750 nm. Microstructure analysis indicated the formation of a dense interfacial structure by grain growth and increase of surface coverage of the perovskite layer with DPPS, and the formation of PbI2 was suppressed, leading to the improvement of photovoltaic properties.

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Facile Synthesis of Spherical TiO2 Hollow Nanospheres with a Diameter of 150 nm for High-Performance Mesoporous Perovskite Solar Cells

Materials ◽

10.3390/ma14030629 ◽

2021 ◽

Vol 14 (3) ◽

pp. 629

Author(s):

Hoang Van Quy ◽

Dang Hai Truyen ◽

Sangmo Kim ◽

Chung Wung Bark

Keyword(s):

Solar Cells ◽

High Performance ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Synthesis Method ◽

Short Circuit Current ◽

Transport Layer ◽

Electron Transport Layer ◽

Hollow Nanospheres ◽

Facile Synthesis

The electron transport layer (ETL) of organic–inorganic perovskite solar cells plays an important role in their power conversion efficiency (PCE). In this study, TiO2 hollow nanospheres with a diameter of 150 nm were prepared by a facile synthesis method. The synthesized TiO2 hollow nanospheres had a highly porous structure with a surface area of 85.23 m2 g−1, which is significantly higher than commercial TiO2 (P25) (54.32 m2 g−1), indicating that they can form an ideal mesoporous layer for Formamidinium iodide-based perovskite solar cells (PSCs). In addition, the nanospheres achieved a remarkable perovskite performance, and the average PCE increased from 12.87% to 14.27% with a short circuit current density of 22.36 mAcm−2, an open voltage of 0.95 V, and a fill factor of 0.65. The scanning electron microscopy images revealed that the enhanced PCE could be due to the improved carrier collection and transport properties of the nanosphere, which enabled efficient filtration of perovskite into the TiO2 mesoporous ETL. The TiO2 hollow nanospheres fabricated in this study show high potential as a high-quality ETL material for efficient (FAPbI3)0.97(MAPbBr3)0.03-based PSCs.

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Passivation Effect of CsPbI3 Quantum Dots on the Performance and Stability of Perovskite Solar Cells

Photonics ◽

10.3390/photonics9010003 ◽

2021 ◽

Vol 9 (1) ◽

pp. 3

Author(s):

Genjie Yang ◽

Dianli Zhou ◽

Jiawen Li ◽

Junsheng Yu

Keyword(s):

Quantum Dots ◽

Solar Cells ◽

Active Layer ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Vacancy Defects ◽

Key Factor

The quality of active layer film is the key factor affecting the performance of perovskite solar cells. In this work, we incorporated CsPbI3 quantum dots (QDs) materials into the MAPbI3 perovskite precursor to form photoactive layer. On one hand, CsPbI3 QDs can be used as nucleation center to enhance the compactness of the perovskite film, and on the other hand, partially CsPbI3 QDs can be dissociated as anions and cations to passivate vacancy defects in the perovskite active layer. As a result, the film quality of the active layer was improved remarkably, thus exciton recombination was reduced, and carrier transfer increased accordingly. The devices based on doped-CsPbI3 QDs film had higher short circuit current, open circuit voltage and filling factor. Finally, the power conversion efficiency (PCE) was greatly enhanced from 14.85% to 17.04%. Furthermore, optimized devices also exhibited better stability. This work provides an effective strategy for the processing of high-quality perovskite films, which is of great value for the preparation and research of perovskite photoelectronic devices.

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Enhanced Efficiency of Halide Perovskite Solar Cells by Solvent Engineering

Journal of Nanoelectronics and Optoelectronics ◽

10.1166/jno.2020.2717 ◽

2020 ◽

Vol 15 (2) ◽

pp. 243-249

Author(s):

Xibin Liu ◽

Jiayou Tao ◽

Gaohua Liao ◽

Zhijun Zou ◽

Fen Li ◽

...

Keyword(s):

Solar Cells ◽

Surface Composition ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Polar Molecules ◽

High Quality ◽

Solvent Engineering ◽

Temperature Solution

During the process of the low-temperature solution fabrication, it always leads to high defects density at the grain boundaries and the interfaces, which are great barriers toward excellent solar cells. Different polar molecules of solvents are brought in to modify the surface composition by tuning the nucleation densities to obtain perovskite films with high crystallization quality. In this work, with efficiently exchanging intramolecular mechanism, high-quality MAPbI3-based perovskite films had been conveniently fabricated. Two kinds of polar molecules of dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP) were added to the dimethylformamide (DMF) solvent to result in perovskite films with high quality. As a result, the device with NMP solvent treatment outputs improved efficiency of 18.5% at the short-circuit current (Jsc) of 23.3 mA cm–2, with an open-circuit voltage (Voc) of 1.075 V and a fill factor of 77.1% under standard AM 1.5 solar illumination. This method of solvent engineering might provide a convenient way for the application of perovskite-based photovoltaic devices.

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High Performance Planar Structure Perovskite Solar Cells Using a Solvent Dripping Treatment on Hole Transporting Layer

Coatings ◽

10.3390/coatings10020127 ◽

2020 ◽

Vol 10 (2) ◽

pp. 127 ◽

Cited By ~ 2

Author(s):

Xuhui Wang ◽

Gang Lu ◽

Min Zhang ◽

Yali Gao ◽

Yanbo Liu ◽

...

Keyword(s):

Solar Cells ◽

Charge Carrier ◽

High Performance ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Solution Treatment ◽

Short Circuit Current ◽

Hole Transport ◽

Transport Layer ◽

Hole Transport Layer

Perovskite solar cell efficiency is not only related with material properties, but also affected by the interface engineering that used in perovskite solar cells. The perovskite film/electrode interface properties play important roles in charge carrier extraction, transport, and recombination. To achieve better interface contact for the device operation, proper interlayers or surface treatment should be applied. In this study, we applied a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) interlayer with a solvent/solution washing treatment as the hole transport layer. It showed that by the solvent/solution treatment, the PEDOT:PSS film conductivity was significantly enhanced, and hence, the charge carrier transfer efficiency was efficiently improved, and the device short-circuit current density was enlarged. Finally, the device efficiency significantly increased from 14.8% to 16.2%.

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High open-circuit voltage and short-circuit current flexible polymer solar cells using ternary blends and ultrathin Ag-based transparent electrodes

Journal of Materials Chemistry A ◽

10.1039/c7ta09033a ◽

2017 ◽

Vol 5 (48) ◽

pp. 25476-25484 ◽

Cited By ~ 15

Author(s):

Quan Liu ◽

Johann Toudert ◽

Laura Ciammaruchi ◽

Guillermo Martínez-Denegri ◽

Jordi Martorell

Keyword(s):

Solar Cells ◽

High Performance ◽

Open Circuit Voltage ◽

Mechanical Stability ◽

Polymer Solar Cells ◽

Short Circuit ◽

Short Circuit Current ◽

Open Circuit ◽

Transparent Electrodes ◽

Flexible Polymer

An optical strategy to design and fabricate ultrathin Ag-based transparent electrodes is developed for high-performance flexible polymer solar cells with robust mechanical stability.

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