Halide Perovskite-based Solar Cells Research Articles

A combined DFT and finite difference simulation study on hybrid halide perovskite-based solar cells

This work reports the modelling and numerical estimation of the photovoltaic parameters of perovskite solar cells (PSCs) containing formamidinium lead iodide (FAPbI3) and formamidinium tin iodide (FASnI3) in the form of light active materials using SCAPS 1D software. The analysis is done by introducing diverse hole and electron transport materials and back metal contacts to identify the most appropriate device configuration that can deliver optimum photovoltaic output. The optoelectronic properties and the absorption spectra of the two compounds are estimated by DFT calculation using WIEN2k, which incorporates density functional theory (DFT) principles and are provided as input to SCAPS 1D to improve the accuracy of modelling study. For FAPbI3 as absorber material, the configuration FTO/IGZO/FAPbI3/NiO/Au shows the highest photovoltaic parameter exhibiting a power conversion efficiency (PCE) and fill factor (FF) of 19.75 % and 74.29 % respectively. With FASnI3 as the absorber material, FTO/PCBM/FASnI3/P3HT/Au gives a PCE and FF of 21.6 % and 67.74 % respectively. The work also includes the analysis of influence of defect density at the interface layers and series and shunt resistance on performance of above-mentioned device architectures to identify their limitations under real experimental conditions. The influence of various attributes of perovskite on the performance of the device is examined to determine their optimum values.

Simulation of perovskite solar cell with transparent contacts for solar windows

In recent years, halide-based perovskite solar cells (PSC) have caught worldwide attention since their power conversion efficiency (PCE) has surpassed 25% with low fabrication cost and high scalability. The semi-transparent PSC (ST-PSC) is suitable for building-integrated photovoltaic (BIPV) applications, especially for solar windows. The ST-PSC must demonstrate a reasonable balance between PCE and transparency in the visible region for solar windows, which is inversely proportional to each other. This work studies ST-PSC based on methylammonium lead triiodide (MAPbI3) as solar windows using the General-Purpose Photovoltaic Device Model (GPVDM) and OPAL 2 as the simulation platforms. Parameters such as methylammonium lead triiodide (MAPbI3) thickness, silver (Ag) contact thickness and indium tin oxide (ITO) transparent contact thickness are investigated in relation to the PCE and average visible transmission (AVT). The results demonstrate that the ST-PSC with MAPbI3 thickness of 500 nm and ITO bottom transparent contact of 100 nm leads to PCE of 22.85% and AVT of 11.36%. These parameters represent the best results obtained in this work.

Transparent Luminescent down-conversion coating for improved performance and enhanced stability of carbon-based perovskite solar cells

Methylammonium lead halide-based perovskite solar cells (PSCs) perform superior photovoltaic performance, nevertheless, demonstrate limited light utilization and instability within the ultraviolet (UV) range. Lanthanide-based down-conversion (DC) materials can mitigate the photoinduced deterioration by resolving spectrum mismatched losses. Particularly, lanthanide complexes possess a broad UV absorbing region thus can convert absorbed UV light to visible or near-infrared light, exhibiting large pseudo-Stoke's shift while they could allow spectrum responsiveness of the PSCs in the UV.Therefore, the DC material may enhance the photovoltaic performance by converting high-energy photons to low-energy photons whilst may also perform as UV shielding material, and finally may both develop PSCs' efficiency and stability. Herein, a novel transparent luminescent down-converting layer (LDC) based on a highly emitting Europium complex in a siloxane matrix was used as an external coating to PSCs with the purpose of improving the solar cells' performance extending their response in the UV region while improving cells’ photostability. The conducted studies indicated that the LDC coating may additionally serve as an anti-reflective and UV-shielding layer simultaneously, resulting in better light-harvesting ability of the perovskite. As a result, short circuit current (Jsc) amplification by the presence of LDC re-emitting the absorbed UV light to the visible and the best carbon-based perovskite solar cell (C-PSC) revealed a 16.13 % overall performance in comparison to the 15.38 % obtained for the control device. Furthermore, photostability tests demonstrated that the unencapsulated LDC-modified devices prepared under ambient conditions retained 75 % of their initial PCE after 8 h under artificial solar light illumination whereas the control devices remained at 40 % at the same conditions. These findings suggest that the LDC layer decreases the UV degradation for PCEs, resulting in PCE and stability enhancement.

Probing elemental diffusion and radiation tolerance of perovskite solar cells via non-destructive Rutherford backscattering spectrometry

Mixed organic–inorganic halide perovskite-based solar cells have attracted interest in recent years due to their potential for both terrestrial and space applications. Analysis of interfaces is critical to predicting device behavior and optimizing device architectures. Most advanced tools to study buried interfaces are destructive in nature and can induce further degradation. Ion beam techniques, such as Rutherford backscattering spectrometry (RBS), is a useful non-destructive method to probe an elemental depth profile of multilayered perovskite solar cells (PSCs) as well as to study the inter-diffusion of various elemental species across interfaces. Additionally, PSCs are becoming viable candidates for space photovoltaic applications, and it is critical to investigate their radiation-induced degradation. RBS can be simultaneously utilized to analyze the radiation effects induced by He+ beam on the device, given their presence in space orbits. In the present work, a 2 MeV He+ beam was used to probe the evidence of elemental diffusion across PSC interfaces with architecture glass/ITO/SnO2/Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3/spiro-OMeTAD/MoO3/Au. During the analysis, the device active area was exposed to an irradiation equivalent of up to 1.62 × 1015 He+/cm2, and yet, no measurable evidence (with a depth resolution ∼1 nm) of beam-induced ion migration was observed, implying high radiation tolerance of PSCs. On the other hand, aged PSCs exhibited indications of the movement of diverse elemental species, such as Au, Pb, In, Sn, Br, and I, in the active area of the device, which was quantified with the help of RBS.

Molecule-bridged electron-selective contact for high-efficiency halide-based perovskite solar cells

This paper achieves efficient and stable PSCs by constructing molecular bridges between the buried interfaces. PSCs passivated by the H2Mi interface molecular bridge have been proven to have a high PCE of 24.34% and excellent light stability.

Experimental and Theoretical Investigations of MAPbX3 -Based Perovskites (X=Cl, Br, I) for Photovoltaic Applications.

This work mainly focuses on synthesizing and evaluating the efficiency of methylammonium lead halide-based perovskite (MAPbX3 ; X=Cl, Br, I) solar cells. We used the colloidal Hot-injection method (HIM) to synthesize MAPbX3 (X=Cl, Br, I) perovskites using the specific precursors and organic solvents under ambient conditions. We studied the structural, morphological and optical properties of MAPbX3 perovskites using XRD, FESEM, TEM, UV-Vis, PL and TRPL (time-resolved photoluminescence) characterization techniques. The particle size and morphology of these perovskites vary with respect to the halide variation. The MAPbI3 perovskite possesses a low band gap and low carrier lifetime but delivers the highest PCE among other halide perovskite samples, making it a promising candidate for solar cell technology. To further enrich the investigations, the conversion efficiency of the MAPbX3 perovskites has been evaluated through extensive device simulations. Here, the optical constants, band gap energy and carrier lifetime of MAPbX3 were used for simulating three different perovskite solar cells, namely I, Cl or Br halide-based perovskite solar cells. MAPbI3 , MAPbBr3 and MAPbCl3 absorber layer-based devices showed ~13.7 %, 6.9 % and 5.0 % conversion efficiency. The correlation between the experimental and SCAPS simulation data for HIM-synthesized MAPBX3 -based perovskites has been reported for the first time.

Advancing Efficiency and Stability of Lead, Tin, and Lead/Tin Perovskite Solar Cells: Strategies and Perspectives

Halide‐perovskite‐based solar cells (HPSCs) have established themselves as a promising photovoltaic (PV) technology in a remarkably short time. The rapid improvement in HPSCs can be attributed to the unique material and optoelectronic properties of metal halide perovskite semiconductors coupled with a very knowledgeable and experienced PV community. This review briefly summarizes the chemistry of halide perovskites, delving into the fundamental aspects of crystal structure and optical bandgap, followed by a more in‐depth report on the advancements in HPSCs efficiencies, thanks to structural regulation, interfacial modulation, and thin‐film engineering. It is mainly focused on three metal halide perovskites topics: 1) high‐performance Pb‐based perovskites, 2) Sn‐based perovskites and their associated challenges, and 3) emerging work on mixed composition Pb–Sn perovskites. For each of these domains, the effects stemming from the tuning of the monovalent A‐site and the halide site are examined. Additionally, various approaches aimed at passivating defects in the bulk film and at the interface, along with carrier transport engineering, are discussed. The discussions also encompass the broader implications for device performance, stability, and material toxicity. Finally, perspectives on the future directions and the commercial feasibility of perovskite photovoltaic technologies are provided.

Performance of Cs-Doped Carbon-Based Perovskite Solar Cells in Ambient Environment

The development of organometal halide-based perovskite solar cells (PSCs) has made remarkable progress in photovoltaics. The commercialization of PSCs is still significantly limited, owing to their poor stability and the high material cost of a hole transport layer (HTL) and metal electrodes. To counter these issues, a carbon-based HTL and noble metal-free PSCs are being used. In this work, the effect of Cs-doping on perovskite film morphology and device performance has been systematically studied because the Cs+ and Br− ions-doping has proved to be a good choice to improve the stability of PSCs in combination with a carbon electrode. The results showed that when the Cs-doping concentration in perovskite film, MA1−xCsxPb(I1−yBry)3, was equal to x = 0.09, there was a substantial change in the morphological and optoelectronic properties of perovskite films. The grain size of perovskite films was improved from 70 nm (x = 0.00 control) to 170 nm (x = 0.09 Cs-doped), reducing grain boundaries. Moreover, the trap states were additionally passivated resulting in improved radiative recombinations in the perovskite film. The device fabrication was carried out in a controlled dry glovebox, with relative humidity < 40% using carbon as a counter electrode. As a result, Cs-doped PSCs showed a significant increase in efficiency (5.27%) compared to control PSCs (1.55%).

Numerical Simulation and Optimization of Inorganic Lead-Free Cs3Bi2I9-Based Perovskite Photovoltaic Cell: Impact of Various Design Parameters

The lead halide-based perovskite solar cells have attracted much attention in the photovoltaic industry due to their high efficiency, easy manufacturing, lightweight, and low cost. However, these lead halide-based perovskite solar cells are not manufactured commercially due to lead-based toxicity. To investigate lead-free inorganic perovskite solar cells (PSCs), we investigated a novel Cs3Bi2I9-based perovskite configuration in SCAPS-1D software using different hole transport layers (HTLs). At the same time, WS2 is applied as an electron transport layer (ETL). Comparative analysis of the various design configurations reveals that ITO/WS2/Cs3Bi2I9/PEDOT:PSS/Au offers the best performance with 20.12% of power conversion efficiency (PCE). After optimizing the thickness, bandgap, defect density, and carrier density, the efficiency of the configuration is increased from 20.12 to 24.91%. Improvement in other performance parameters such as short circuit current (17.325 mA/cm2), open circuit voltage (1.5683 V), and fill factor (91.66%) are also observed after tuning different attributes. This investigation indicates the potential application of Cs3Bi2I9 as a lead-free and stable perovskite material that can contribute to improving the renewable energy sector.

Nanoscale Thermal Strain Engineering-Driven Ferroelastic Domain Evolution in CH3NH3PbI3 Perovskites.

A local thermal strain engineering approach via an ac-heated thermal probe was incorporated into methylammonium lead triiodide (MAPbI3) crystals and acts as a driving force for ferroic twin domain dynamics, local ion migration, and property tailoring. Periodically, striped ferroic twin domains and their dynamic evolutions were successfully induced by local thermal strain and high-resolution thermal imaging, giving decisive evidence of the ferroelastic nature in MAPbI3 perovskites at room temperature. Local thermal ionic imaging and chemical mappings demonstrate that domain contrasts are from local methylammonium (MA+) redistribution into the stripes of chemical segregation in response to the local thermal strain fields. The present results reveal an inherent coupling among local thermal strains, ferroelastic twin domains, local chemical-ion segregations, and physical properties and offer a potential path to improve the functionality of metal halide perovskite-based solar cells.

Methylammonium-free co-evaporated perovskite absorbers with high radiation and UV tolerance: an option for in-space manufacturing of space-PV?

With a remarkable tolerance to high-energetic radiation and potential high power-to-weight ratios, halide perovskite-based solar cells are interesting for future space PV applications. In this work, we fabricate and test methylammonium-free, co-evaporated FA0.7Cs0.3Pb(I0.9Br0.1)3 perovskite solar cells that could potentially be fabricated in space or on the Moon by physical vapor deposition, making use of the available vacuum present. The absence of methylammonium hereby increased the UV-light stability significantly, an important factor considering the increased UV proportion in the extra-terrestrial solar spectrum. We then tested their radiation tolerance under high energetic proton irradiation and found that the PCE degraded to 0.79 of its initial value due to coloring of the glass substrate, a typical problem that often complicates analysis. To disentangle damage mechanisms and to assess whether the perovskite degraded, we employ injection-current-dependent electroluminescence (EL) and intensity-dependent VOC measurements to derive pseudo-JV curves that are independent of parasitic effects. This way we identify a high radiation tolerance with 0.96 of the initial PCE remaining after 1 × 1013 p+ cm-2 which is beyond today's space material systems (<0.8) and on par with those of previously tested solution-processed perovskite solar cells. Together our results render co-evaporated perovskites as highly interesting candidates for future space manufacturing, while the pseudo-JV methodology presents an important tool to disentangle parasitic effects.

Recent advances in carbon-based materials for high-performance perovskite solar cells: gaps, challenges and fulfillment.

Presently, carbon-based nanomaterials have shown tremendous potential for energy conversion applications. Especially, carbon-based materials have emerged as excellent candidates for the fabrication of halide perovskite-based solar cells, which may lead to their commercialization. In the last decade, PSCs have rapidly developed, and these hybrid devices demonstrate a comparable performance to silicon-based solar cells in terms of power conversion efficiency (PCE). However, PSCs lag behind silicon-based solar cells due to their poor stability and durability. Generally, noble metals such gold and silver are employed as back electrode materials during the fabrication of PSCs. However, the use of these expensive rare metals is associated with some issues, urgently necessitating the search for cost-effective materials, which can realize the commercial applications of PSCs due to their interesting properties. Thus, the present review shows how carbon-based materials can become the main candidates for the development of highly efficient and stable PSCs. Carbon-based materials such as carbon black, graphite, graphene nanosheets (2D/3D), carbon nanotubes (CNTs), carbon dots, graphene quantum dots (GQDs) and carbon nanosheets show potential for the laboratory and large-scale fabrication of solar cells and modules. Carbon-based PSCs can achieve efficient and long-term stability for both rigid and flexible substrates because of their high conductivity and excellent hydrophobicity, thus showing good results in comparison to metal electrode-based PSCs. Thus, the present review also demonstrates and discusses the latest state-of-the-art and recent advances for carbon-based PSCs. Furthermore, we present perspectives on the cost-effective synthesis of carbon-based materials for the broader view of the future sustainability of carbon-based PSCs.

Structural, electronic, optical, elastic, thermodynamic and thermal transport properties of Cs2AgInCl6 and Cs2AgSbCl6 double perovskite semiconductors using a first-principles study.

In this study, we employ the framework of first-principles density functional theory (DFT) computations to investigate the physical, electrical, bandgap and thermal conductivity of Cs2AgInCl6-CAIC (type I) and Cs2AgSbCl6-CASC (type II) using the GGA-PBE method. CAIC possesses a direct band gap energy of 1.812 eV, while CASC demonstrates an indirect band gap energy of 0.926 eV. The CAIC and CASC exhibit intriguingly reduced thermal conductivity, which can be attributed to the notable reduction in their respective Debye temperatures, measuring 182 K and 135 K, respectively. The Raman active modes computed under ambient conditions have been compared with real-world data, showing excellent agreement. The thermal conductivity values of CAIC and CASC compounds exhibit quantum mechanical characteristics, with values of 0.075 and 0.25 W m-1 K-1, respectively, at 300 K. It is foreseen that these outcomes will generate investigations concerning phosphors and diodes that rely on single emitters, with the aim of advancing lighting and display technologies in the forthcoming generations.

Recent Advancements in Tin Halide Perovskite-Based Solar Cells and Thermoelectric Devices.

The excellent optoelectronic properties of tin halide perovskites (Sn-PVKs) have made them a promising candidate for replacing toxic Pb counterparts. Concurrently, their enormous potential in photon harvesting and thermoelectricity applications has attracted increasing attention. The optoelectronic properties of Sn-PVKs are governed by the flexible nature of SnI6 octahedra, and they exhibit extremely low thermal conductivity. Due to these diverse applications, this review first analyzes the structural properties, optoelectronic properties, defect physics, and thermoelectric properties of Sn-PVKs. Then, recent techniques developed to solve limitations with Sn-PVK-based devices to improve their photoelectric and thermoelectric performance are discussed in detail. Finally, the challenges and prospects for further development of Sn-PVK-based devices are discussed.

Strain-Manipulated Photovoltaic and Photoelectric Effects of the MAPbBr3 Single Crystal.

Lead halide perovskite materials, such as MAPbBr3 and MAPbI3, show excellent semiconductor properties, and thus, they have attracted a lot of attention for applications in solar cells, photodetectors, etc. Here, a periodic strain can dynamically manipulate the build-in electric field (Ebi) of the depletion region with piezoelectricity at the Au/MAPbBr3 interface. As a result, the photovoltaic short-circuit current density (Jsc) and the open-circuit voltage (Voc) are increased by 670 and 82%, respectively, by applying an external strain upon an asymmetric solar-cell-like Au/MAPbBr3/Ga structure. Furthermore, the equivalent piezoelectric d33 values of ∼3.5 pC/N are confirmed in the Au/MAPbBr3/Au structure with both the sinusoidal strain and the 405 nm light illumination with 220 mW/cm2 upon one semitransparent Au electrode. This study not only proves that pressure can effectively enhance the energy conversion efficiency of the halide perovskite-based solar cells and light detectors but also supposes a multifunctional sensor, which can detect light intensity, sense dynamic pressure, explore accelerated speed, etc. simultaneously.

Defect Pair Formation in FAPbI3 Perovskite Solar Cell Absorbers.

Formamidinium lead iodide (FAPbI3) based hybrid perovskite light absorbers have shown remarkable performance in recent years. Since they have unique set of optoelectronic characteristics, they are considered as a good candidate absorber material for future solar cell applications. Until recently, much research had focused on the quantitative analysis of point defects on halide-based perovskite solar cells. Studies show that understanding defect mechanisms in perovskites has a huge impact on efficiency and stability improvements; however, such mechanisms have not been fully understood yet. Here, using first-principles calculations, we investigate the possible defect pair formations in FAPbI3, characterized by their formation energies and charge transitions. We found that while some donor and acceptor point defects are unstable and shallow when they are isolated, they form stable and deep-trap defect pairs and potentially limit the optoelectronic performance. We anticipate that our results will influence future discussions on the impact of defect formation on the performance and stability of perovskite solar cells.

Sequential Passivation for Lead-Free Tin Perovskite Solar Cells with High Efficiency.

Lead-free tin perovskite solar cells (PKSCs) have attracted tremendous interest as a replacement for toxic lead-based PKSCs. Nevertheless, the efficiency is significantly low due to the rough surface morphology and high number of defects, which are caused by the fast crystallization and easy oxidization. In this study, a facile and universal posttreatment strategy of sequential passivation with acetylacetone (ACAC) and ethylenediamine (EDA) is proposed. The results show that ACAC can reduce the trap density and enlarge the grain size (short-circuit current (Jsc ) enhancement), while EDA can bond the undercoordinated tin and regulate the energy level (open-circuit voltage (Voc ) enhancement). A promising 13 % efficiency is achieved with better stability. In addition, other combinations of diketones or amines are selected, with similar effects. This study provides a universal strategy to enhance the crystallinity and passivate defects while fabricating stable PKSCs with high efficiency.

Lansoprazole, a cure-four, enables perovskite solar cells efficiency exceeding 24%

The practical applications of organic–inorganic hybrid metal halide-based perovskite solar cells (PSCs), as the fastest growing photovoltaic devices, are limited by the further improvement of their stability and performance. Additive engineering is considered as a hopeful strategy to alleviate these issues. Herein, Lansoprazole (Lanz), as a multifunctional additive, has four effects for ameliorating the stability and performance of PSCs. The strong hydrophobic trifluoromethyl group on Lanz can cover atop of perovskite to build a moisture-oxygen-barrier; The high electron-donating sulfinyl moiety on Lanz can provide lone electron pair to lead ions to passivate defects; The modification of Lanz can adjust Fermi-level of perovskite and optimize the energy match of functional layers; The introduction of Lanz can moderate the growth rate of perovskite, improve crystal quality and reduce grain boundaries and defects. Consequently, the Lanz-modified device achieves an excellent PCE of 24.05% compared to the pristine device (PCE of 21.91%). Meanwhile the modified device possesses excellent environmental and operational stability that maintains 84% of its initial PCE under continuous irradiation for 500 h.

THE SYNTHESIS OF METHYLAMMONIUM LEAD IODIDE ON MESOPORE TiO2 THIN FILM APPLYING OSTWALD RIPENING PROCESS UNDER AMBIENT CONDITION

Organometallic halide-based perovskite solar cells have played a significant role in the development of photovoltaic technology. The synthesis of the perovskite usually needs specific atmospheres, especially controlled humidity. Here, we demonstrate the synthesis of compact methylammonium lead iodide perovskite (MAPbI3) on TiO2 under ambient conditions through one and two-step spin-coating deposition methods, which both resulted in an unconverted PbI2 on the films. The two-step method provided a higher amount of PbI2 regarding the reaction of methyl ammonium iodide (MAI) with an outer layer of the first bonded PbI2 hindered the inner layer to interact with MAI. The Ostwald ripening (OR) process that was applied to the thin film resulted through one-step deposition synthesis has successfully converted the unformed PbI2 to MAPbI3 with a more uniform, lower void, and higher crystal size as confirmed by XRD and SEM analysis results. The application of MAPbI3 prepared using OR treatment in the solar cell resulted in higher efficiency (7.64%) than the one synthesized without OR (4.91%).

A short review on progress in perovskite solar cells

The performance of hybrid metal halide perovskite-based solar cells has been improved at an exceptional rate compared to other solar cells. Just in a decade, the efficiency of perovskite solar cells (PSC) could be increased from 3.8% to 25.5%. The halide-based perovskite materials have gained increased attention for optoelectronics applications because of their simple synthesis method and the ability to achieve high-efficiency solar cells. In this article, we have reviewed the significant developments in PSC that have contributed to the high-efficiency achievements. These include the evolution of device structure, the development of absorber layer materials as well as charge selective layers, and the advancement in the device fabrication techniques targeting to improve the control over perovskite film morphology, crystallinity, composition, and the interface properties of the devices leading to enhancement in the overall performances. We have also discussed the challenges and prospects for PSC research and development towards commercialization.