The number of publications on perovskite solar cells (PSCs) continues to grow exponentially. Although the efficiency of PSCs has exceeded 25.5%, not every research laboratory can reproduce this ...result or even pass the border of 20%. Unfortunately, it is not always clear which dominating mechanism is responsible for the performance drop. Here, a simple method of light intensity analysis of the JV parameters is developed, allowing an understanding of what the mechanisms are that appear in the solar cell and limit device performance. The developed method is supported by the drift‐diffusion model and is aimed at helping in the explanation of parasitic losses from the interface or bulk recombination, series resistance, or shunt resistance in the perovskite solar cell. This method can help not only point toward the dominating of bulk or interface recombination in the devices but also determine which interface is more defective. A detailed and stepwise guidance for such a type of light intensity analysis of JV parameters is provided. The proposed method and the conclusions of this study are supported by a series of case studies, showing the effectiveness of the proposed method on real examples.
Light intensity analysis of photovoltaic parameters is introduced as a simple method, allowing understanding of the dominating mechanisms limiting the device performance in perovskite solar cells. The method is based on the drift‐diffusion model and is aimed at helping in the explanation of parasitic losses from the trap‐assisted recombination or ohmic losses in devices.
The production of electronic devices using solution based (“wet”) deposition technologies has some decisive technical and commercial advantages compared to competing approaches like vacuum based ...(“dry”) manufacturing. Particularly, the potential to scale up production processes to large areas and high volumes by introducing continuous roll‐to‐roll (R2R) methods on flexible substrates has been the topic of intense studies from both applied research institutes and industry already for some years. Decisive steps forward have been achieved during that time, resulting in the dawn of commercial applications for a number of processes, while additional development work is still needed in some other fields. This review summarizes the work published during the last few years on the R2R printing and wet coating of electronic devices. An overview is presented of the basic operational principles for the most commonly used R2R printing and coating methods and techniques for proper web handling in R2R lines. Then, the most commonly used types of flexible substrate materials are introduced, followed by a review of the work published in the application areas of transparent conductor materials, printed electric connections, light emitting devices, photovoltaic energy generation, printed logic, and sensing.
This manuscript presents an overview of roll‐to‐roll production processes for flexible and printed electronics using solution based (“wet”) deposition technologies. The application areas covered include transparent conductors, printed circuitry, light emitting and photovoltaic devices, printed logic, and sensors.
The feasibility of upscaling the perovskite solar cells technologies to high volume production using roll‐to‐roll (R2R) slot die coating is demonstrated in this study. Perovskite solar cells are ...produced by R2R slot die coating on flexible substrates with a width of 30 cm and the web speed of 3–5 m min−1. R2R deposition of the electron transport layer and perovskite is performed at ambient atmosphere from nontoxic solvents compatible with industrial manufacturing. The average stabilized power conversion efficiency of the devices made on different areas of the foil is 12%, with the best value of 13.5%. The demonstrated achievement is an important milestone and a big solid step toward future commercialization of perovskite‐based solar cells technologies.
Perovskite solar cells produced by roll‐to‐roll (R2R) slot die coating on flexible substrates at ambient atmosphere from nontoxic solvents demonstrate an average stabilized efficiency of 12%, with the best value of 13.5%. This study is the first public demonstration of R2R slot die coating of perovskites on 30 cm wide substrates with the deposition and drying speed of 3–5 m min−1.
Scalable sheet-to-sheet slot die coating processes have been demonstrated for perovskite solar cells and modules. The processes have been developed on 6in. × 6in. glass/ITO substrates for two ...functional layers: the perovskite photo-active layer and the Spiro-OMeTAD hole transport layer. Perovskite solar cells produced using these slot die coating processes demonstrate device performances identical to the spin coated devices. All manufactured devices illustrate a high level of reproducibility. The developed slot die coating processes were also used for the manufacturing of perovskite PV modules. Large area modules of 12.5 × 13.5cm2 were realized by slot die coating on 6in. × 6in. substrates in combination with newly developed laser ablation processes for conventional P1-P2-P3 monolithic cell interconnections. The modules demonstrate power conversion efficiencies above 10%, with a power output of 1.7W. This achievement is an important milestone in the development of up-scalable manufacturing technologies for perovskite PV modules.
•Scalable sheet-to-sheet slot die coating processes have been demonstrated for perovskite solar cells and modules.•Slot die coated devices demonstrate PCEs identical to the spin coated devices.•Large area modules of 12.5 × 13.5cm2 were realized by slot die coating on 6in. × 6in. substrates.•Laser ablation processes for conventional P1-P2-P3 monolithic cell interconnections have been developed.•The modules demonstrate power conversion efficiencies above 10%, with a power output of 1.7W.
In order to achieve the highest performance of organometal trihalide perovskite solar cells, it is required to recognize the dominant mechanisms which play a key role in a perovskite material. In the ...following studies, we have focused on the interfacial recombination between the hole transporting layer (HTL) and the perovskite CH3NH3PbI3 in solar cell devices with p–i–n architecture. It has been shown that Cu:NiOx used as HTL drastically decreases a short–circuit photocurrent (Jsc) and an open–circuit voltage (Voc). However, we have found that an addition of PTAA thin layer improves cells quality and, as a consequence, the efficiency of such solar cells increases by 2%. Here, we explain both Jsc and Voc losses with a theory of the “dead layer” of perovskite material where a very high surface recombination occurs. We demonstrate the numerical and experimental studies by the means of series detailed analyses to get in–depth understanding of the physical processes behind it. Using a drift–diffusion model, it is shown that the presence of a parasitic recombination layer influences mostly the current distribution in the simulated samples explaining Jsc and Voc losses. The following results could be useful for improving the quality of perovskite solar cells.
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•Interfacial recombination with the theory of the “dead layer” is studied.•Very high surface recombination in the dead layer leads to the Voc and Jsc losses.•Passivation with PTAA thin layer reduces the surface recombination and increases the efficiency of such solar cells by about 2%.•The electrical drift–diffusion model is used to prove the concept of recombination layer.
Research progress in hybrid perovskite solar cells has increased enormously over the last years, making perovskites very promising candidates for future PV technologies. Perovskite solar cells use ...abundant and low-cost starting materials, providing economic advantages for large-scale implementation. A transition from laboratory-scale fabrication to industrial manufacturing requires scaling up of the dimension of the devices; manufacturing of large-area modules, considering the development of interconnection as an important step toward upscaling; and development of deposition methods alternative to spin coating, which are industrially compatible and facilitate high power conversion efficiency of the manufactured devices. This Perspective provides an overview of the recent developments toward industrial-scale manufacturing. Advances and perspectives in the developments of sheet-to-sheet and roll-to-roll deposition methods are discussed along with other related technologies required for industrial-scale methods, e.g., laser ablation, drying, post-treatment, and the use of alternative industry-compatible solvents for manufacturing of perovskite solar cells.
The development of hybrid organic–inorganic halide perovskite solar cells (PSCs) that combine high performance and operational stability is vital for implementing this technology. Recently, ...reversible improvement and degradation of PSC efficiency have been reported under illumination–darkness cycling. Quantifying the performance and stability of cells exhibiting significant diurnal performance variations is challenging. We report the outdoor stability measurements of two types of devices showing either reversible photo-degradation or reversible efficiency improvement under sunlight. Instead of the initial (or stabilized) efficiency and T 80 as the figures of merit for the performance and stability of such devices, we propose using the value of the energy output generated during the first day of exposure and the time needed to reach its 20% drop, respectively. The latter accounts for both the long-term irreversible degradation and the reversible diurnal efficiency variation and does not depend on the type of process prevailing in a given perovskite cell.
Perovskite solar cells (PSCs) have celebrated a decade of investigation as a promising photovoltaic technology. However, they contain lead, so inorganic lead-free PSCs can be designed as green and ...clean energy sources. To overcome the current obstacles in lead-free PSCs, the stability and performance gap should be minimized. The drift-diffusion simulation model is a conducive way to understand the working mechanism in a thin-film solar cell. Here we adopted a computational approach to design and investigate the performance of CsSn
0.5
Ge
0.5
I
3
as a light harvester. We optimize the thickness of the perovskite, for its use in an inverted planar structure (FTO/PCBM/CsSn
0.5
Ge
0.5
I
3
/Spiro-OMeTAD/Au). Furthermore, cerium oxide (CeO
x
) and PTAA are used as alternative electron and hole transport layers, respectively. We studied the effect of trap density in the bulk CsSn
0.5
Ge
0.5
I
3
and its impact on performance, recombination rate, and diffusion length. The open-circuit voltage (
V
oc
) showed a significant improvement and the correlation with the trap density at the interface layers is established. We noted that the defect density at the perovskite/hole selective layer interface has a profound impact on the performance of lead-free PSCs as compared to the electron selective layer/perovskite interface. After optimizing defect parameters, the lead-free PSC can deliver a PCE of 24.20%, with
V
oc
= 1170 mV,
J
sc
= 25.80 mA cm
−2
, and FF = 80.33%. Our findings provide access guidelines and pave the way for lead-free PSCs based on the Sn-Ge combination to approach their limit.
We computed lead free perovskite solar cells based on CsSn
0.5
Ge
0.5
I
3
can delivered a PCE of 24.20% and unravel the kinetics by Drift-Diffusion simulation. Perovskite/HTM interface was quantify as the "magic" interface that controls the performance.
The operational stability of perovskite solar cells (PSCs) remains a limiting factor in their commercial implementation. We studied the long-term outdoor stability of ...ITO/SnO2/Cs0.05((CH3NH3)0.15(CH(NH2)2)0.85)0.95PbI2.55Br0.45/spiro-OMeTAD/Au cells, as well as the dynamics of their degradation, under simulated sunlight indoors and their recovery in the dark. The extent of overall degradation was found to depend on processes occurring both under illumination and in the dark, i.e., during the daytime and nighttime, with the dynamics varying with cell aging. Full recovery of efficiency in the dark was observed for cells at early degradation stages. Further cell degradation resulted in recovery times much longer than one night, appearing as irreversible degradation under real operational conditions. At later degradation stages, very different dynamics were observed: short-circuit current density and fill factor exhibited a pronounced drop upon light turn-off but strong improvement under subsequent illumination. The interplay of reversible and irreversible degradation processes with different recovery dynamics was demonstrated to result in changes in the cell’s diurnal PCE dependence during its operational lifespan under real sunlight conditions.
Abstract
The stability of perovskite photovoltaics is a very hot topic nowadays because a long lifetime of the devices is one of the main conditions required for the commercialization of perovskite ...technologies. Although a lot of research on stability has been done on small solar cells, there is not too much information about the stability of the modules. A very important question arises: whether the stability of the modules is different from the stability of the individual cells. With the future goal of scale-up perovskite PV technology, it is important to understand possible the degradation mechanisms which are specific to the modules. This perspective article highlights the stability issues, which are unique to modules but not observed in small cells.
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