Fig 3 - uploaded by Julian C Pena
Content may be subject to copyright.
-cos vs 4 s in. curves, from which the value of micro-stress was estimated, both from MAPI films (deposited by three different methods) and from an FA 0.4 MA 0.6 PbI 3 film deposited by spin coating.
Source publication
This paper reports results of a study on the impact that the synthesis method and the replacement of the methylammonium (MA) cation by the formamidinium (FA) cation have on both morphology and degradation of MAPbI3 (MAPI) films when these are exposed to environmental conditions.
This study was conducted with samples deposited using different routes...
Contexts in source publication
Context 1
... D is the crystallite size, is the wavelength of the CuK radiation, k is a constant equal to 0.94, hkl is the peak width at half-maximum (FWHM) ) value and hkl is the peak position. Plotting the term cos with respect to 4 s in. for the preferred orientation peaks, the strain can be obtained from the slope of the fitted line. Fig. 3 shows curves of cos vs 4 s in., obtained for a typical sample of MAPI prepared by the three different methods that were previously described. The effect of incorporating FA (molar ratio FA / MA = 0.4) in the MAPI lattice on the cos vs 4 s in. curve is also displayed. The inset of Fig. 3 shows the values of the micro-stress , estimated ...
Context 2
... strain can be obtained from the slope of the fitted line. Fig. 3 shows curves of cos vs 4 s in., obtained for a typical sample of MAPI prepared by the three different methods that were previously described. The effect of incorporating FA (molar ratio FA / MA = 0.4) in the MAPI lattice on the cos vs 4 s in. curve is also displayed. The inset of Fig. 3 shows the values of the micro-stress , estimated for the four MAPI samples analyzed. Table 1 shows the minimum value, maximum value, average value and standard deviation of the Table 1 -Statistical parameters of the micro-stress , obtained by means of a statistical analysis performed on several samples of parameter , obtained through a ...
Context 3
... results of Fig.3 show that the substitution of the MA cation by the FA cation in the MAPI lattice gives rise to an increase in the value of the micro-stress , indicating that the substitution of MA by FA in the structure of the compound MAPbI 3 induces formation of structural defects, apparently as a result of the difference between the ionic radius of the FA (2.79 Å) and that of the MA (2.70 Å). ...
Context 4
... results of Fig. 3 also reveal that the synthesis method of the MAPI compound significantly affects the value of , being the samples deposited sequentially in two stages those with the lowest value of , indicating that these synthesis routes favor the growth of MAPI films with a lower density of native and structural ...
Similar publications
This paper reports results of a study on the impact that the synthesis method and the replacement of the methylammonium (MA) cation by the formamidinium (FA) cation have on the degradation of MAPbI3 films when these are exposed to environmental conditions. This study was conducted with samples deposited using different routes based on growth method...
Citations
... Over the years, it has been shown that the semiconducting polymers are capable of achieving reasonably highpower conversion efficiencies, as proved by the research findings by Li et al. [3]. These polymers are inexpensive to synthesize and can be solution-processed in a roll printing technique, demonstrating high stability, as studied by Gordillo et al. [4]. Inherently poor polymer properties, such as low exciton diffusion lengths and low mobilities, can be overcome by nanoscale morphology. ...
Considering the temporary ecological challenges confronting our global milieu, the imperative to transition towards sustainable and conscientious methodologies looms as an unequivocal necessity. As purveyors of scientific inquiry our mandate is to meticulously explore a plethora of alternatives, liberating ourselves from the shackles of deleterious energy sources. We are investigating the value of semiconducting polymer-based solar cells in this work from a material science perspective because they are quite affordable to synthesize and have demonstrated some encouraging results, due to its notable benefits in photovoltaic (PV) applications, such as its high absorption coefficients, excellent charge carrier mobility, and favorable blend morphology with acceptor materials, which all contribute to improved device performance. We are using poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) in this study. In order to investigate the impact of the Methylammonium Lead Iodide Perovskite (MAPI3) thin film on the performance of the ITO/TiO2/MEH-PPV/Au solar cell, a numerical simulation was carried out using SCAPS-1D. Open circuit voltage (Voc), density of short circuit (Jsc), fill factor (FF), efficiency (η), and other solar cell metrics were measured and analyzed, with special emphasis to device inputs and the ensuing improvements. The performance of the MEH-PPV/TiO2 solar cell has been enhanced by the addition of MAPI3, resulting in a noteworthy 14% efficiency boost. These modelling results can be very useful for a better understanding and control of this type of solar cells.
... They allow expecting the future investigations in order to ameliorate the materials performance. MAPI3 perovskite-based films were recently investigated by several authors (e.g., [3,4,12,[17][18][19][20][21][22]), however, the novelty of the subject makes it very open and further investigations still being needed and are expected to contribute in reinforcing the availability of these materials for their optoelectronic uses. In this paper, a MAPI3 perovskite thin film synthesized by the sol gel-spray ultrasonic method. ...
In this work, methylammonium lead halide CH3NH3PbI3 (MAPI3) perovskite nanorods were synthesized by the sol gel-spray ultrasonic method. The XRD pattern exhibits peaks assigned to the tetragonal MAPI3 structure with a residual PbI2 phase. SEM and AFM images show the formation of nanorods like picture with rough surface. The Raman spectrum was visualized to show various vibration modes in the film. Photoluminescence data revealed one emission peak at 786 nm (1.58 eV) in the band gap band, which was confirmed by the UV-Vis spectrum. The slight difference between the found band gap energy and the ideal one is explained in terms of shallow trap states.
... The passivating shell on the grain surface hinders the visible absorption, but it stimulates the ultraviolet absorption and the centres of non-radiative recombination centres. These intermediate centres play a key role in weakening the internal structure that leads to decomposition [40][41][42][43][44][45]. ...
This research encompasses a comprehensive investigation of stable metal halide perovskite materials, with a focus on bandgap tuning, crystallization pathways, and the impact of moisture. To study the moisture effects on the optical properties of Methylammonium perovskites, a UV-VIS spectrophotometer was employed, providing valuable insights into their hydrophilic nature and spectroscopic properties. Additionally, morphological, and structural characterization further enhanced our understanding of the microstructure and crystallographic properties. We also explored the materials' response to intense light through the Z scan technique, examining their nonlinear optical properties. The study's findings play a pivotal role in advancing our knowledge and facilitating the development of more stable and versatile perovskite materials for practical applications. Subsequently, simulations were conducted using the Solar Cell Capacitance Simulator SCAPS 1D, revealing a promising solar cell architecture with a glass substrate/FTO/(CH3NH3)2CuCl4/spiro-OMeTAD/Au configuration, showcasing an impressive conversion efficiency of 27.93%, along with a fill factor of 84.16, Jsc of 34.39 mA/cm2, and Voc of 0.9 V.
... However, despite its tremendous potential, perovskite MAPbI3 faces certain challenges that need to be addressed for its widespread adoption, especially in solar applications. These challenges include issues related to structure, temperature, moisture, and time stabilities [16][17][18]. Many efforts from the researchers have been spent to overcome these issues [19][20][21][22]. ...
Doping of perovskite solar cells is a regularly used approach to adjust and modify the structures and properties of organic-inorganic hybrid perovskite such as CH3NH3PbI3 material, and subsequently increase the conversion efficiency. In this work, optical absorption is calculated for copper-doped-perovskite material based on the density functional theory analysis for tetragonal crystal structures. We investigated the effect of doping CH3NH3PbI3 with copper, as an optical alternative to Pb atom in central tetragonal structure. As a conclusion, some enhancements of the optical properties by the replacement of Cu by the Pb atom are observed, such as optical absorption at certain visible spectrum regions, along with more intensive field mapping. This optical enhancement can lead to a better improvement of perovskite solar cell according to metallic-doing substitutional defect concept.
... This advantage was attributed to a lower density of structural defects and grain boundaries. 272 More recently, Dewi et al. also reported the absence of tensile stress and strain in co-evaporated MAPbI 3 , enabling intrinsically stable films and devices at high temperatures, in contrast to strained and unstable spin-coated MAPbI 3 films. 46 Strain-free TE is a highly appealing choice of deposition method, as strained halide perovskite exhibits poorer optoelectronic properties. ...
The development of perovskite photovoltaics has so far been led by solution-based coating techniques, such as spin-coating. However, there has been an increasing interest in thermal evaporation (TE) as an industrially compatible method to fabricate perovskite solar cells (PSCs). TE has several advantages compared with solution processing, including a high degree of process control, excellent film uniformity, low material consumption, conformal substrate coverage, a lack of toxic solvents, and superb device reproducibility and scalability. These benefits make TE an ideal choice to upscale lab-scale PSCs into modules. Here, we discuss three types of TE-based perovskite deposition techniques, namely 1-step TE, multistep all-TE, and multistep hybrid of TE-gas reaction and TE-solution processing. We summarize their fundamental principles and applications, first on small-area PSCs and then on modules. Finally, we provide our outlook on important research topics for TE PSCs, namely device interlayers, defect passivation, and device stability.
... MAPbI 3 is sensitive to external stability factors like moisture and illumination (Ogunniran and Martins, 2021). Otherwise, Gordello et al. proves that MAPbI 3 deposited in a two-step procedure improves the stability of the device associated with an improvement of their morphology by increasing the grain size and with low density of structural defects (Gordillo et al., 2020). Also, a detailed study reported that the dissolution of MAPbI 3 under dark when exposed to H 2 O improves the stability of the device by forming a molecular hydrate compound (Ogunniran and Martins, 2021). ...
This work aims to analyze the stability of Perovskite solar cells PSCs using machine learning (ML) techniques. An extremely randomized tree technique, trained with a dataset containing 1050 perovskite device samples with different materials, deposition methods, and storage conditions, is used. Pushing by its non-linearity and randomity, this approach is an intriguing choice for decreasing the variance of the total model. The effects of data inputs on the stability of the device are investigated by analyzing the Decision Trees (DT) constituent of the Extra Trees (ET) while the feature importance technique was used for feature engineering. The two techniques' findings are compared with previous experimental results for screening the most optimized manufacturing materials and storage conditions for long-term stability. For regular cells, TiO2/m-TiO2 as electron transport layer (ETL), (2D-3D) perovskite as active layer, P3HT and LiTFSi + TBP as hole transport layer (HTL), and HTL second layer, and Carbon as back contact were found to enhance the device stability with DMF+DMSO as precursor solution and Chlorobenzene as an anti-solvent solution. For inverted cells, BCP and PCBM, MAPBl3-xClx, NiO, and DEA, Al back contact were found to improve stability. The obtained results provide evidence of the aptness of the proposed ML strategy in captivating the suitable combination of different layer materials, deposition methods, and storage conditions. Besides, the adopted method unveils the importance of manufacturing techniques in realizing efficient and stable solar cells.
... In order to overcome this problem, other highly efficient materials, e.g., hybrid halide perovskites, which can potentially be deposited on large areas using printing processes, are being researched [1,2]. Nevertheless, these materials are not long-lasting due to their degradation through humidity, temperature, and UV light [3]. Other promising materials could be ferroelectric perovskites due to their bulk photovoltaic effect [4]. ...
Ferroelectric materials have gained high interest for photovoltaic applications due to their open-circuit voltage not being limited to the band gap of the material. In the past, different lead‑based ferroelectric perovskite thin films such as Pb(Zr,Ti)O3 (Pb,La)(Zr,Ti)O3 and PbTiO3 were investigated with respect to their photovoltaic efficiency. Nevertheless, due to their high band gaps they only absorb photons in the UV spectral range. The well-known ferroelectric PbFe0.5Nb0.5O3 (PFN), which is in a structure similar to the other three, has not been considered as a possible candidate until now. We found that the band gap of PFN is around 2.75 eV and that the conductivity can be increased from 23 S/µm to 35 S/µm during illumination. The relatively low band gap value makes PFN a promising candidate as an absorber material.
... The faster PCE degradation for SC_MAPbI 3 as compared to the pure film, Figure S11C, Supporting Information, is related to poorer perovskite robustness and pinholes formation under high-temperature aging. The superior thermal stability of coevaporated MAPbI 3 films is in line with the improved ambient stability in high humidity (≈80 RH) of vacuum processed MAPbI 3 films as compared to the solution-based film showed by Gordillo et al. [72] ...
Thermal stability is a critical criterion for assessing the long‐term stability of perovskite solar cells (PSCs). Here, it is shown that un‐encapsulated co‐evaporated MAPbI3 (TE_MAPbI3) PSCs demonstrate remarkable thermal stability even in an n‐i‐p structure that employs Spiro‐OMeTAD as hole transport material (HTM). TE_MAPbI3 PSCs maintain over ≈95% and ≈80% of their initial power conversion efficiency (PCE) after 1000 and 3600 h respectively under continuous thermal aging at 85 °C. TE_MAPbI3 PSCs demonstrate remarkable structural robustness, absence of pinholes, or significant variation in grain sizes, and intact interfaces with the HTM, upon prolonged thermal aging. Here, the main factors driving TE_MAPbI3 stability are assessed. It is demonstrated that the excellent TE_MAPbI3 thermal stability is related to the perovskite growth process leading to a compact and almost strain‐stress‐free film. On the other hand, un‐encapsulated PSCs with the same architecture, but incorporating solution‐processed MAPbI3 or Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3 as active layers, show a complete PCE degradation after 500 h under the same thermal aging condition. These results highlight that the control of the perovskite growth process can substantially enhance the PSCs thermal stability, besides the chemical composition. The TE_MAPbI3 impressive long‐term thermal stability features the potential for field‐operating conditions. Long‐term thermal stability is critical for perovskite solar cells (PSCs)'s operation. Un‐encapsulated co‐evaporated MAPbI3 PSCs, contrarly to similar spin‐coated PSCs, exhibit remarkable structural robustness and retain 80% of their initial efficiency after 3600 h aging at 85 °C. This excellent intrinsic stability is driven by the strain‐stress‐free MAPbI3 grown by co‐evaporation, where post‐annealing is not required to fully form the perovskite.
In this work, we investigated the effect of two different substrate types on the structural and optical characteristics of the CH3NH3PbI3 perovskite layer: soda-lime glass (SLG) and borosilicate glass (UTG). Subsequently, we examined the samples' stability by measuring their absorbance following 120 hours of exposure to the local ambient conditions in Djelfa, Algeria. The absence of OH groups in the UTG substrate as revealed by FTIR may be the reason for the notable impact of the UTG substrate over the SLG substrate on perovskite characteristics. This absence indicates that the inorganic element's influence on the perovskite significantly diminishes, and in this instance, the matrix endures for an extended period within the local metrological restrictions.
Organohalide perovskite nanocrystals (OHPNCs) and their wide range of optoelectronic applications have attracted much interest due to their unparalleled photoluminescent intensity and quantum efficiency. Furthermore, their band gap is tunable over the visible and near-infrared wavelengths through changes in composition, shape, or size. However, OHPNCs are unstable under ambient conditions due to their high reactivities with moisture and gases. In this work, the stability of methylammonium lead iodide (MAPbI3) perovskite suspension and dried films against heat and water was enhanced through the addition of tetraethyl orthosilicate (TEOS). With the SiO2 coating, the photoluminescence (PL) of MAPbI3 nanocrystals increased by 30% and the MAPbI3 films were stable in ambient environment for several weeks. The enhancement of stability can be further improved by adding the TEOS in steps and increasing the time interval between the steps. Furthermore, the silica-coated MAPbI3 perovskite nanocrystals were made into photodetectors demonstrating their practical applications in ambient condition.
Graphical abstract
