Solid solutions of perovskite oxides (KNbO3)1-x+(La2NiMnO6)x (x=0, 0.1, 0.2 and 0.3) with a variation of band gap (1.33-3.6 eV) have been introduced as a promising photovoltaic absorber. The structural characterization of the prepared samples was carried out using X-ray diffraction (followed by Rietveld refinement) and Raman experiment. As the doping percentage of the monoclinic La2NiMnO6 in the solid-solution increases, the crystal structure of host KNbO3 becomes more symmetric from orthorhombic to cubic. A large reduction in the particle size has also been observed in the solid solutions in comparison to the pure KNbO3. The band gap (~ 1.33 eV) of the synthesized solid solution x=0.1 is found to be very close to the Shockley-Queisser band gap value of 1.34 eV, which suggests the promising photovoltaic possibility in this material. Photoluminescence (PL) emission spectra reveal a strong PL quenching in the solid-solutions in comparison to the KNbO3. The overall structural and optical studies suggest the promising photovoltaic possibility in KNbO3/ La2NiMnO6 solid solution.
In recent years, halide perovskite-based solar cells have received intensive attention, and demonstrated power conversion efficiency as high as 25.8%. With regard to the toxicity of Pb and the instability of organic elements, all inorganic lead-free perovskites (ILPs) have been extensively studied to achieve comparable or greater photovoltaic performance. In order to develop ILPs as an alternative for solar cell applications, we performed first-principles calculations of ABBr3 perovskites (A = Cs, Rb, K, and Na, and B = Sn, and Ge). Structural, electronic, and optical properties were systemati…
Third-generation photovoltaic (PV) materials combine many advantageous properties, including a high optical absorption together with a large charge carrier mobility, facilitated by small effective masses. Halide perovskites (ABX3, where X is I, Br or Cl) appear to be the most promising third-generation PV materials at present. Their opto-electronic properties are governed by the B-X bond. A quantum-chemical bond analysis reveals that this bond differs significantly from ionic, metallic or covalent bonds. Instead, it is better regarded as metavalent, since it shares approximately one p-electron…
Photochemical stability of encapsulated films of mixed halide perovskites with a range of MAPb(I1-xBrx)3 compositions (solid solutions) was investigated under accelerated stressing using concentrated sunlight. Evolution of light absorption and the corresponding structural modifications in the films were recorded by UV-vis spectroscopy and X-ray diffraction (XRD), respectively. MAPbBr3 film exhibited no degradation. In MAPbI3 and mixed halide MAPb(I1-xBrx)3 films, decomposition of the perovskite material with crystallization of inorganic PbI2, and the corresponding degradation of light absorpti…
Data-driven approaches to solve problems in materials science have gained immense popularity in recent times due to their ability to predict unknown material properties and uncover relationships between structure and property. Machine learning algorithms like GBRT, random forest and neural networks have had tremendous success in predicting target properties of materials and design of structures for various applications. However, a major drawback for achieving results within the required accuracy using these algorithms has been the need for large datasets which can be challenging for problems w…
BiFeO$_{3}$ is multiferroic material with space group Pbnm exhibits coupling of both magnetic and electric orders under strain force. To analyze band gap Tauc plot extrapolation method is used $\&$ remarkably smaller than some reported literature values for space group R3c structure. The dielectric function $\varepsilon(ω)$ demonstrated that light energy upon transition through BiFeO$_{3}$ has shown a decline inconsistent pattern with index of refraction variation in range of 13 to 8, 8 to 5, 5 to 3, $\&$ 3 to 1 as per photon energy. Moreover, non crossing degenerate energy level and hybridize…
Halide perovskites have outstanding photovoltaic properties which have been optimized through interfacial engineering. However, as these materials approach the limits imposed by the physics of semiconductor junctions, it is urgent to explore alternatives, such as the bulk photovoltaic effect, whose physical origin is different and not bound by the same limits. In this context, we focus on the flexo-photovoltaic effect, a type of bulk photovoltaic effect that was recently observed in oxides under strain gradients. We have measured the flexo-photovoltaic effect of MAPbBr3 and MAPbI3 crystals und…
This study is carried out using first principles density functional theory calculations within gpaw code. Atomic size effect is analyzed and investigated by doping either Li, Cs or both on Barium doped BiFeO$_3$ (BFO) which belongs to monoclinic $P2_1/m$ space group. The calculated results reveal that Cs doped BFO had significantly improved photocurrent density seemingly due to broadened absorption peaks and biplasmons generation. Co-doping two atoms with large size difference have a significant effect on plasmon width and peak than doping with a single and small sized atom. At higher photon e…
Lead-halide perovskites have demonstrated astonishing increases in power conversion efficiency in photovoltaics over the last decade. The most efficient perovskite devices now outperform industry-standard multi-crystalline silicon solar cells, despite the fact that perovskites are typically grown at low temperature using simple solution-based methods. However, the toxicity of lead and its ready solubility in water are concerns for widespread implementation. These challenges, alongside the many successes of the perovskites, have motivated significant efforts across multiple disciplines to find …
High-Throughput Photovoltaic Screening and Spacer-Dependent Shift Current in Two-Dimensional Hybrid Perovskites
Humboldt-Universität zu Berlin（柏林洪堡大学）；Institute of Materials Science, Technische Universität Darmstadt（达姆施塔特工业大学材料科学研究所）；North University of China（中北大学）；State Key Laboratory of Extreme Environment Optoelectronic Dynamic Measurement Technology and Instrument（极端环境光电动态测量技术与仪器国家重点实验室）；Materials Genome Institute, Shanghai University（上海大学材料基因组研究院）；Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China（福建省光电信息科技创新实验室）
Circularity in Perovskite-Based Tandem Photovoltaics for Terawatt-Scale Deployment
University of Toulouse, Toulouse INP, CNRS, LGC（图卢兹大学）；Inorganic Chemistry Laboratory, University of Oxford（牛津大学无机化学实验室）；Department of Mechanical Engineering, University of Bath（巴斯大学机械工程系）；Environment and Sustainability Institute, University of Exeter（埃克塞特大学环境与可持续发展研究所）；Department of Mechanical and Energy Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University（伊玛姆阿卜杜勒拉赫曼·本·费萨尔大学工程学院机械与能源工程系）；Department of Materials, University of Oxford（牛津大学材料系）
SAM Molecular Stacking with Heterogeneous Orientationfor High-Performance Perovskite Photovoltaics
Soochow University（苏州大学）；Shanghai Advanced Research Institute, Shanghai Institute of Applied Physics Chinese Academy of Sciences（中国科学院上海应用物理研究所上海先进研究院）；Marmara University（马尔马拉大学）；S.U. Umarov Physical-Technical Institute of the National Academy of Sciences of Tajikistan（塔吉克斯坦国家科学院S.U.乌马罗夫物理技术研究所）
First-principles prediction into robust high-performance photovoltaic double perovskites A$_{2}$SiI$_{6}$ (A = K, Rb, Cs)
尽管在有机-无机杂化钙钛矿太阳能电池中获得超过23%的光伏效率，但具有期望带隙的稳定材料是罕见的并且是高度期望的。借助第一性原理计算，我们预测了一类新的无毒无机双钙钛矿（DP），即硅基卤化物A $_{2}$ SiI $_{6}$（A = K，Rb，Cs; X = Cl，Br，I）.该家族含有地球上丰富的Si，可用于钙钛矿太阳能电池（PSC）。特别是A型$_{2}$ Si I $_{6}$具有优良的物理特性，包括0.84-1.15 eV的合适的带隙，分散的下导带，小的载流子有效质量，在可见光范围内的宽光子吸收。重要的是，在高温下的良好稳定性使它们成为有前途的太阳能电池的光吸收剂。
Lead-free halide double perovskites are promising stable and non-toxic alternatives to methylammonium lead iodide in the field of photovoltaics. In this context, the most commonly used double perovskite is Cs$_2$AgBiBr$_6$, due to its favorable charge transport properties. However, the maximum power conversion efficiency obtained for this material does not exceed 3\%, as a consequence of its wide indirect gap and its intrinsic and extrinsic defects. On the other hand, the materials space that arises from the substitution of different elements in the 4 lattice sites of this structure is large a…
Perovskite solar cells (PSCs) with superior performance have been recognized as a potential candidate in photovoltaic technologies. However, the defects in active perovskite layer induce non-radiative recombination which restricts the performance and stability of the PSCs. The construction of thiophene-based 2D structure is one of the significant approaches for surface passivation of hybrid PSCs that may combine the benefits of the stability of 2D perovskite with the high performance of 3D perovskite. Here, a sulfur-rich spacer cation 2-thiopheneethylamine iodide (TEAI) is synthesized as a pas…
Interfaces between the perovskite active layer and the charge-transport layers (CTLs) play a critical role in both efficiency and stability of halide-perovskite photovoltaics. One of the major concerns is that surface defects of perovskite could cause detrimental nonradiative recombination and material degradation. In this work, we addressed this challenging problem by inserting ultrathin alkali-fluoride (AF) films between the tri-cation lead-iodide perovskite layer and both CTLs. This bilateral inorganic walls strategy makes use of both physical-blocking and chemical-anchoring functionalities…
Methyl-ammonium lead iodide perovskite crystallizes in different structures depending on the temperature: orthorhombic, tetragonal and cubic. An important point to be considered is the effect of the microscopic properties of the different structures on the optical and photovoltaic properties. Using first principles we obtain the absorption coefficients that will determine the absorption of solar radiation. In order to analyze the contributions of the different atoms to the absorption coefficients we split them into a many-species expansion. Using a similar methodology we also split the efficie…
Composition Anisotropy Drives Large Bulk Photovoltaic Fields Along the Non-polar Vertical Direction in 2D Hybrid Perovskite Ferroelectrics
Heidelberg University（海德堡大学）；Universität Heidelberg（海德堡大学）；NTNU Norwegian University of Science and Technology（挪威科技大学）；Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences（中国科学院福建物质结构研究所）；Technical University of Darmstadt（达姆施塔特工业大学）；Graz University of Technology（格拉茨工业大学）
This work is aimed to study mixed-cation (hybrid methyl ammonium plus inorganic cations) halide perovskites using first principles Density Functional Theory (DFT) formalism in order to find their potential applications in perovskite based photovoltaics. This is an addition to the two previous studies performed by the author on high-throughput screening of hybrid halide and inorganic halide perovskites. This work involves mixing certain amounts of the inorganic cation to the organic site (methyl ammonium) and study the electronic structure of the resultant. 63 perovskites have been simulated in…
Genome-Guided Interpretable Screening of Phase-Stable, Lead-Free Double Perovskite Absorbers for All-Inorganic Semiconductors, Sensors, and Photovoltaics with DFT-Validated Design Rules
Research and Analysis Institute, RAI Initiative Ltd（拉伊倡议有限公司研究与分析研究所）；Bangladesh University of Textiles（孟加拉国纺织大学）；Universiti Putra Malaysia（马来西亚博特拉大学）；Institute of Science Tokyo（东京科学大学）；University of Évora（埃武拉大学）；Daffodil International University（达富迪尔国际大学）；University of Idaho（爱达荷大学）；North Carolina A&T State University（北卡罗来纳州立农业技术大学）
Chalcogenide perovskites have emerged as non-toxic and stable photovoltaic materials, acting as an alternative to lead halide hybrid perovskites having similar optoelectronic properties. In the present work, we report the electronic and optical properties of chalcogenide perovskites AZrS$_3$ (A=Ca, Sr, Ba) by using the density functional theory (DFT) and many-body perturbation theory (MBPT viz. G$_0$W$_0$ and BSE). This study includes excitonic analysis for the aforementioned systems. The exciton binding energy (E$_\textrm{B}$) is found to be larger than that of the halide perovskites, as the …
