Perovskite Solar Cell Technology Research Articles

Progress and challenges on scaling up of perovskite solar cell technology

In this review, developments and challenges related to scaling up of PSCs are discussed. This work touches the aspects of scalable deposition methods, technical challenges, costs, and large area perovskite single and tandem devices.

The emergence of concentrator photovoltaics for perovskite solar cells

The emergence of high-efficiency photovoltaic research is undergoing intense study and is technologically desirable to meet sustainable energy and environmental demand. However, every single solar cell has a theoretical power conversion efficiency limit, and, thus, without compromising the cost, the power conversion efficiency enhancement of a solar cell is highly challenging. As a convenient solution, concentrating photovoltaics can focus sunlight onto an extremely high-efficiency solar cell integrating various optics. Concentrating photovoltaics use optical devices that collect and redirect the light toward the smaller photovoltaic cell and reduce the demand for the mined elements required for the solar cell fabrication. The research interest from the photovoltaic community has concentrated on organic-inorganic hybrid halide perovskite absorbers, and nowadays, perovskite solar cells manifest their outstanding contribution among the low-cost photovoltaic technologies. Inevitably, large-area perovskite solar cells suffer a lot with their poor stability, hindering their commercialization pace. Thus, the implementation of concentrating photovoltaic technology in perovskite solar cells demonstrates an inherent advantage using a smaller size solar cell. This review provides an overview of concentrating photovoltaic technology implementation, including their recent research and development portfolio, their economic benefits in combination with inexpensive optical elements and tracking systems, limitations, challenges, and relative scope of the future study, focusing on the emerging perovskite solar cell technology.

Numerical simulation design of all-inorganic hole-transport-layer-free CsSnI3 (Sn-rich)/CsSnI3 perovskite efficient solar cells

As perovskite solar cell (PSC) technology is about to be commercialized, the use of toxic and organic material is still a problem. At the same time, hole-transport-layer-free (HTL-free) PSCs have received widespread attention given their simple structure and low manufacturing cost. In this study, we use the wxAMPS software to produce a simulation, using C s S n I 3 ( S n - r i c h ) / C s S n I 3 all-perovskite as the absorption layer and carbon as the back electrode, as well as to propose a new, to the best of our knowledge, inorganic HTL-free PSC. C s S n I 3 is a narrowband material whose absorption range can be extended to the near-infrared spectral region; it also has very high hole mobility and so can be used as both the light absorption layer and the HTL. Compared with that of standard structure devices, the photoelectric conversion efficiency (PCE) of the PSC is better. When the perovskite layer thickness is 900 nm, the optimal PCE is 14.91%, the open-circuit voltage is 0.81 V, the short-circuit current is 23.77 m A / c m 2 , and the fill factor is 77.37%. Our research further found that C s S n I 3 (Sn-rich) has the best PCE at 10 18 ∼ 10 19 / c m 3 . When the electron transport layer and the light absorption layer conduction band offset is − 0.2 e V , the PCE has an optimal value of 15.02%. Finally, by changing the light temperature, the PCE value of our study is between 12.07% and 16.61% under non-extreme work environments, and the results show that the device has good thermostability. This proves that the proposed all-inorganic HTL-free PSCs have broad prospects in future photovoltaic and optoelectronics applications and provide theoretical guidance for the manufacture of non-toxic and inorganic PSCs.

Costing Analysis of Scalable Carbon-Based Perovskite Modules Using Bottom Up Technique.

In recent years, perovskite solar cells (PSCs) have achieved a remarkable power conversion efficiency of 25.5%, indicating that they are a promising alternative to dominant Si photovoltaic (PV) technology. This technology is expected to solve the world's energy demand with minimal investment and very low CO2 emissions. The market has shown a lot of interest in PSCs technology. A technoeconomic analysis is a useful tool for tracking manufacturing costs and forecasting whether technology will eventually achieve market‐driven prices. A technoeconomic analysis of a 100 MW carbon‐based perovskite solar module (CPSM) factory located in India is presented in this paper. Two CPSMs architectures—high‐temperature processed CPSMs (Module A) and low‐temperature processed CPSM's (Module B)—are expected to offer minimum sustainable prices (MSPs) of $ 0.21 W‐1 and $ 0.15 W‐1. On the basis of MSP, the levelized cost of energy (LCOE) is calculated to be 3.40 ¢ kWh‐1 for module A and 3.02 ¢ kWh‐1 for module B, with a 10‐year module lifetime assumption. The same modules with a 25‐year lifespan have LCOEs of 1.66 and 1.47 ¢ kWh‐1, respectively. These estimates are comparable to market dominant crystalline silicon solar modules, and they are also favorable for utilizing perovskite solar cell technology.

The critical issue of using lead for sustainable massive production of perovskite solar cells: a review of relevant literature.

This work aims to review the most significant studies dealing with the environmental issues of the use of lead in perovskite solar cells (PSCs). A careful discussion and rationalization of the environmental and human health toxicity impacts, evaluated by life cycle assessment and risk assessment studies, is presented. The results of this analysis are prospectively related to the possible future massive production of PSC technology.

Organic additives in all-inorganic perovskite solar cells and modules: from moisture endurance to enhanced efficiency and operational stability

Power conversion efficiency (PCE) of perovskite solar cells (PSC) has been skyrocketed to certified 25.5% owing to their improved and tunable optoelectronic properties. Although, various strategies have been adopted to date regarding PCE and stability enhancement within PSC technology, certain instability factors (moisture, heat, light) are hindering their commercial placement. Recently, all-inorganic PSCs got hype in the photovoltaic research community after they attained PCE > 20% and due to their significant endurance against heat and light mishmashes, but there only left moisture sensitivity as the only roadblock for their industrial integration. Here, we review the recent progress of additive inclusion into all-inorganic (CsPbX3) PSCs to stabilize their intrinsic structure and to withstand the performance limiting factors. We start with the detailed description of chemical instability of different perovskite compositions, phase segregation, and how organic molecules and dyes help to repair the structural defects to improve the overall PCE and stability of PSCs. Moisture endurance as a result of chemical passivation through organic additives, low-dimensional inorganic PSCs to enhance device stability and scalable fabrication of CsPbX3 PSCs are also reviewed. The challenges of module degradation and design implications with proposed strategies and outlook are interpreted in the ending phrases of this review.

Integration of Intense Pulse Light Annealing for Rapid Scalable Fabrication of Roll to Roll Slot Die Coated Perovskite Solar Cells

Perovskite Solar Cells (PSCs) is an exciting new photovoltaic technology and holds a great promise to reduce the cost of solar energy production. Flexible PSCs can offer an unique pathway towards manufacturing of terawatt-scale solar photovoltaic technology, it involves the fabrication of large area mass production of PSCs and modules by incredibly high throughput roll-to-roll (R2R) processing. Therefore, there is a great possibility of commercializing PSC technology through roll-to-roll printing method. Beyond high throughput R2R processing, flexible PSCs will also enable more diverse applications for solar energy harvesting including, their facile integration into buildings, consumer electronics, automobiles, and various other portable applications. The feasibility of upscaling the PSC technologies to a high-volume production using R2R slot-die coating is demonstrated in this study. Several attempts have been explored to optimize the slot-die coating technique to fabricate large-area PSCs on flexible ITO-coated PET (ITO/PET) substrates. PSCs are fabricated by R2R slot die coating on flexible ITO/PET substrates with the width of 6 inches and the web speed of 2 m/min. Initially, it involves R2R deposition of SnO2 electron transport layer (ETL), followed by a photoactive perovskite (MAPbI3) layer at ambient conditions compatible with industrial manufacturing. These coatings were developed by optimizing an appropriate meniscus length, flow rate, and drying conditions for attaining good quality films. Intense Pulse Light (IPL) annealing is integrated into the R2R allowing for rapid crystallization of SnO2 and Perovskite films within fraction of seconds by using high energy pulses at different pulse intervals. It eliminates the use of conventional ovens for thermal annealing and enables cost-effective large-scale production of Perovskite films and their corresponding solar cells rapidly. As obtained films were used for the device fabrication by spinning of Spiro-OMeTAD solution as a hole transporting layer and thermal evaporation of MoOx as a buffer layer and silver (Ag) as a top contact. The average stabilized power conversion efficiency (PCE) of devices made from different areas of the large area films is nearly 10% with an active are of 1cm2. The demonstrated achievement is very promising and paves an easy route towards future commercialization of perovskite-based solar cells technologies via R2R slot-die coating method. Figure 1

Optimization of various terminal topologies of bifacial perovskite/FeSi2 tandem solar cell

Although perovskite (PVK) and bifacial solar cell technologies have gained a rapid emergence in recent years, integration of PVK with low-cost high-efficiency subcell in a bifacial tandem structure is still an area of huge interest. In this work, the potential of FeSi2 thin film solar cell to be used as bottom subcell in a PVK based bifacial tandem cell structure is explored. We use self-consistent electrical-optical model to investigate various terminal topologies of PVK/FeSi2 bifacial tandem solar cell. In particular, we compare a novel three terminal four junction (3T-4J) tandem configuration termed as twin (or double) tandem cell with conventional monolithic two terminal (2T) and mechanically stacked four terminal (4T) bifacial tandem structures having two junction (2J) configuration. We show that the optimal thickness of PVK in 2T-2J tandem configuration is strongly dependent upon magnitude of albedo due to the current-matching constraint between the subcells, whereas both 4T-2J and 3T-4J tandem cells can perform optimally for a broad range of albedo. At optimal cell design, all tandem structures could exhibit efficiency >27.5% at average Earth albedo of ∼30%. Lastly, the results presented in this work provide a complete design space for optimal cell operations and would be beneficial for the development of low-cost high-efficiency PVK based bifacial tandem solar cell.

Efficient and Stable Perovskite Large Area Cells by Low-Cost Fluorene-Xantene-Based Hole Transporting Layer

Among the new generation photovoltaics, perovskite solar cell (PSC) technology reached top efficiencies in a few years. Currently, the main objective to further develop PSCs is related to the fabrication of stable devices with cost-effective materials and reliable fabrication processes to achieve a possible industrialization pathway. In the n-i-p device configuration, the hole transporting material (HTM) used most is the highly doped organic spiro-fluorene-based material (Spiro-OMeTAD). In addition to the high cost related to its complex synthesis, this material has different issues such as poor photo, thermal and moisture stability. Here, we test on small and large area PSCs a commercially available HTM (X55, Dyenamo) with a new core made by low-cost fluorene–xantene units. The one-pot synthesis of this compound reduces 30 times its cost with respect to Spiro-OMeTAD. The optoelectronic performances and properties are characterized through JV measurement, IPCE (incident photon to current efficiency), steady-state photoluminescence and ISOS stability test. SEM (scanning electron microscope) images reveal a uniform and pinhole free coverage of the X55 HTM surface, which reduces the charge recombination losses and improves the device performance relative to Spiro-OMeTAD from 16% to 17%. The ISOS-D-1 stability test on large area cells without any encapsulation reports an efficiency drop of about 15% after 1000 h compared to 30% for the reference case.

Sequentially Slot‐Die‐Coated Perovskite for Efficient and Scalable Solar Cells

AbstractDevelopment of industrially relevant thin‐film deposition processes is a necessity for upscaling the perovskite solar cell technology to commercial product‐level. This work reports on a sequential deposition method for state‐of‐the art triple cation perovskite by slot‐die coating. During this two‐step process, first, a layer of lead iodide mixed with cesium iodide is deposited, followed by applying the organic cations on top, inducing conversion to perovskite during a second slot‐die coating step. By carefully tuning the ink composition and the deposition parameters, uniform perovskite layers of 5 × 10 cm2 are obtained. Power conversion efficiencies up to 19% for small laboratory solar cells adopting a planar device configuration and up to 15.2% for mini‐modules with an aperture area of 12 cm2 are presented. These values are among the highest efficiencies achieved in the literature for slot‐die‐coated perovskite.

Dopants for Enhanced Performance of Tin-Based Perovskite Solar Cells—A Short Review

Lead-based perovskite solar cells had reached a bottleneck and demonstrated significant power conversion efficiency (PCE) growth matching the performance of traditional polycrystalline silicon solar cells. Lead-containing perovskite solar cell technology is on the verge of commercialization and has huge potential to replace silicon solar cells, but despite the very promising future of these perovskite solar cells, the presence of water-soluble toxic lead content is a growing concern in the scientific community and a major bottleneck for their commercialization. The less toxic, tin-based perovskite solar cells are promising alternatives for lead-free perovskite solar cells. Like lead-based perovskite, the general chemical formula composition of tin-based perovskite is ASnX3, where A is a cation and X is an anion (halogen). It is evident that tin-based perovskites, being less-toxic with excellent photoelectric properties, show respectable performance. Recently, numerous studies reported on the fabrication of Sn-based perovskite solar cells. However, the stability of this novel lead-free alternative material remains a big concern. One of the many ways to stabilize these solar cells includes addition of dopants. In this context, this article summarizes the most important fabrication routes employing dopants that have shown excellent stability for tin-based perovskite photovoltaics and elaborates the prospects of lead-free, tin based stable perovskite photovoltaics.

Simulated development and optimized performance of narrow-bandgap CsSnI3-based all-inorganic perovskite solar cells

As perovskite solar cell (PSC) technology is about to be commercialized, the use of toxic and organic material is still a problem. At the same time, CsSnI3 has received widespread attention because of its narrow bandgap and non-toxicity. In this study, we use the wxAMPS tool to investigate the limitations of Sn-based all-inorganic PSCs, using CsSnI3 perovskite as the absorption layer and Au as the back electrode to create non-toxic all-inorganic PSCs. CsSnI3 is a narrow-band material; the absorption range can be extended to the near-infrared spectral region, and it has a very high hole mobility. Therefore, this article first compares several potential inorganic electron and hole transport layers (ETLs and HTLs), and the results show that C60 ETL and MoOx HTL are the most suitable materials. Moreover, the device performance is further improved by optimizing the absorber thickness as well as the doping density. Under optimized conditions, a conversion efficiency of 19.25% is obtained for the FTO/C60/CsSnI3/MoOx/Au PSCs, indicating that there is much room for further performance enhancement. The photovoltaic performance parameters achieve their optimum value at an absorber thickness is better among the range of 100–1300 nm and doping density of 1019 cm−3. This shows that the proposed non-toxic all-inorganic PSCs have broad prospects in future photovoltaic and optoelectronics applications, and provide theoretical guidance for the manufacture of a non-toxic and inorganic PSCs.

Facile lattice tensile strain compensation in mixed-cation halide perovskite solar cells

Despite the rapid development of power conversion efficiency (PCE) for halide perovskite solar cells (PSCs), the lattice strain engineering in perovskite thin films has been rarely probed in recent years. Herein, a strain compensation by homogeneous crystallization in perovskite films is achieved with the aid of precursor aging in the mixed-cation perovskite of Cs0.05(FA0.83MA0.17)Pb(I0.90Br0.10)3 with near 20% PCE in inverted devices. The homogeneous crystallization releases the residual tensile stress and induces more compressive stress at the edges of perovskite films, thus elongating the carrier lifetime and reducing the trap-assisted carrier recombination. The high dependence on the perovskite components in strain engineering strategy was systematically revealed, wherein MAPbI3 and Cs0.05(FA0.83MA0.17)PbI3 film showed an increased compressive strain and FAPbI3 film showed adverse tensile strain after aging. The density functional theory (DFT) calculations are further performed to reveal the change of electronic features. The precursor aging-induced strain modulation was correlated with a systematic characterization of the charge carrier transport and recombination dynamics in the mixed-cation perovskite films. We believe that this facile approach provides a novel strain engineering strategy for PSCs technology.

One‐Step Slot‐Die Coating Deposition of Wide‐Bandgap Perovskite Absorber for Highly Efficient Solar Cells

Slot‐die coating is a promising technique paving the way for large‐area perovskite deposition and commercially relevant solar device fabrication with sharp control over the thickness and material composition. However, before transferring perovskite solar cells technology to commercial applications, it is required to develop ink formulations, guaranteeing high homogeneity over a wide surface and leading to large, defect‐free, and well‐crystallized perovskite grains to maximize the device performances. A one‐step slot‐die deposition route, combining ink tailoring and vacuum aspiration solvent extraction, affording the deposition of a high‐bandgap multication perovskite, is reported. One important key is the introduction of methylammonium chloride in the ink formulation, which substantially enhances the film quality over a large area. Although the efficacy of antisolvent dripping is demonstrated on a small area, it is not compatible with larger areas. This work compares the latter with a vacuum quench protocol, allowing efficient extraction of the solvents. Considering both ink formulation engineering and vacuum solvent extraction, a stabilized power conversion efficiency of up to 17.5% is reached. This constitutes, to the best of our knowledge, the highest reported value for a high‐bandgap absorber deposited by slot‐die coating. Moreover, stability over 180 h under maximum power point conditions is herein demonstrated.

Low Temperature Processed Fully Printed Efficient Planar Structure Carbon Electrode Perovskite Solar Cells and Modules

AbstractScalable deposition processes at low temperature are urgently needed for the commercialization of perovskite solar cells (PSCs) as they can decrease the energy payback time of PSCs technology. In this work, a processing protocol is presented for highly efficient and stable planar n–i–p structure PSCs with carbon as the top electrode (carbon‐PSCs) fully printed at fairly low temperature by using cheap materials under ambient conditions, thus meeting the requirements for scalable production on an industrial level. High‐quality perovskite layers are achieved by using a combinatorial engineering concept, including solvent engineering, additive engineering, and processing engineering. The optimized carbon‐PSCs with all layers including electron transport layer, perovskite, hole transport layer, and carbon electrode which are printed under ambient conditions show efficiencies exceeding 18% with enhanced stability, retaining 100% of their initial efficiency after 5000 h in a humid atmosphere. Finally, large‐area perovskite modules are successfully obtained and outstanding performance is shown with an efficiency of 15.3% by optimizing the femtosecond laser parameters for the P2 line patterning. These results represent important progress toward fully printed planar carbon electrode perovskite devices as a promising approach for the scaling up and worldwide application of PSCs.

Ambient Air Blade‐Coating Fabrication of Stable Triple‐Cation Perovskite Solar Modules by Green Solvent Quenching

Although halide perovskite solar cell (PSC) technology reaches, in few years, efficiencies greater than 25%, the cost‐ceffective perspective is achievable only if scalable processes in real manufacturing conditions (i.e., pilot line and/or plant factory) are designed and optimized for the full device stack. Herein, a full semiautomatic scalable process based on the blade‐coating technique is demonstrated to fabricate perovskite solar modules in ambient conditions. An efficient and stable triple‐cation cesium methylammonium formamidinium (CsMAFA) perovskite is deposited in ambient air with a two‐step process assisted by air and green anti‐solvent quenching. The developed industry compatible coating process enables the fabrication of several highly reproducible small‐area cells on module size substrate with an efficiency exceeding 17% and with high reproducibility. Corresponding reproducible modules (less than 2% variability) with a 90% geometrical fill factor achieve an efficiency larger than 16% and T 80 = 750 h in light‐soaking condition at maximum power point and room temperature/ambient after encapsulation. Film deposition properties are assessed by different characterization techniques, namely, scanning electron microscopy, profilometry, UV–vis and photoluminescence (PL) spectroscopy, and PL and electroluminescence imaging. The techniques confirm less defects and local coating variations of the ambient air/bladed devices with respect to the nitrogen air/spinned devices.

Effects of the location and size of plasmonic nanoparticles (Ag and Au) in improving the optical absorption and efficiency of perovskite solar cells

Organometal halide perovskite has a vast variety of facilities and possibilities that makes them emerge in perovskite solar cell (PSC) technology. Interaction of incident light with plasmonic nanoparticles (NPs) leads to the formation of an electric field around the NPs. The electric field from plasmonic NPs can enhance the possibility of incident light absorption inside the active layer (AL). In this paper, the light scattering mechanism is used to investigate the effect of plasmonic NPs on the value of carrier generation rate and absorption in PSCs. The finite element method (FEM) under normal-angle sunlight (AM 1.5 G) was used to obtain open-circuit voltage (Voc) and short-circuit current density (Jsc) and as well as efficiency in the proposed structure PSC. The use of gold (Au) and silver (Ag) compositions in the structure of the plasmonic NP results in an increase of the AL absorption, over planar structures. In the simulation results, we showed that the performance of the device is highly dependent on the location of the plasmonic NP in different layers of the PSC as well as the radius of these NPs. Placing the NP in the hole transfer layer (HTL) with the radius of 30 nm and composition of Ag resulted Jsc of 20.31 mA/cm2, Voc of 0.94 V, and the power conversion efficiency (PCE) of 16.20%.

The critical issue of using lead for sustainable massive production of perovskite solar cells: a review of relevant literature

This work aims to review the most significant studies dealing with the environmental issues of the use of lead in perovskite solar cells (PSCs). A careful discussion and rationalization of the environmental and human health toxicity impacts, evaluated by life cycle assessment and risk assessment studies, is presented. The results of this analysis are prospectively related to the possible future massive production of PSC technology.

Hysteresis-free perovskite solar cells with compact and nanoparticle NiO for indoor application

The perovskite solar cell technology is showing rapid progress in delivering high power conversion efficiency. This is not limited to conventional 1 SUN illumination, but state-of-the-art results have also been also demonstrated for a low-light condition such as indoor illumination. In this work, we show that very efficient low-light perovskite solar cells can be realized in the inverted configuration with the use of NiO as a hole transporting material by employing a conventional high-temperature process (300 °C, compact NiO) or a low-temperature process (<100 °C) based on nanoparticle NiO. The power density of 90.2 μW/cm2 at 1000 lux was achieved for compact NiO device, while 71.6 μW/cm2 was obtained with nanoparticle NiO cells under the same illumination. A detailed electrical, optical, and morphological characterization permitted to identify the reasons for the difference between compact and nanoparticle NiO. Beside the difference in power density, nanoparticle NiO permitted to realize the first low temperature inorganic hole transporting layer for low-light p-i-n perovskite solar cell and, as we show, this could be easily scaled up to 1 cm2 without suffering for performance losses moving from small to large area.

Laser Processing Optimization for Large-Area Perovskite Solar Modules

The industrial exploitation of perovskite solar cell technology is still hampered by the lack of repeatable and high-throughput fabrication processes for large-area modules. The joint efforts of the scientific community allowed to demonstrate high-performing small area solar cells; however, retaining such results over large area modules is not trivial. Indeed, the development of deposition methods over large substrates is required together with additional laser processes for the realization of the monolithically integrated cells and their interconnections. In this work, we develop an efficient perovskite solar module based on 2D material engineered structure by optimizing the laser ablation steps (namely P1, P2, P3) required for shaping the module layout in series connected sub-cells. We investigate the impact of the P2 and P3 laser processes, carried out by employing a UV pulsed laser (pulse width = 10 ns; λ = 355 nm), over the final module performance. In particular, a P2 process for removing 2D material-based cell stack from interconnection area among adjacent cells is optimized. Moreover, the impact of the P3 process used to isolate adjacent sub-cells after gold realization over the module performance once laminated in panel configuration is elucidated. The developed fabrication process ensures high-performance repeatability over a large module number by demonstrating the use of laser processing in industrial production.