Perovskite single crystals (PSCs) are intriguing choices for various optoelectronic device applications, such as photo-detectors, solar cells, and LEDs. Triple-cation mixed-halide perovskites exhibit better (phase, thermal, and environmental) stability, then the traditional perovskites based on single cation, and single halide anion. In this work, novel triple-cation mixed-halide PSCs, i.e., FA0.85MA0.10Cs0.05Pb(I0.95Br0.05)3 was synthesized via ACN antisolvent additive-based inverse temperature crystallization (ITC) and its wavelength-dependent photoresponse was investigated. The PSCs exhibited a bandgap energy of 1.45 eV, with a strong photoluminescence emission peak. The crystallinity and morphology of the PSCs were investigated using an X-ray diffractometer (XRD), and scanning electron microscopy (SEM). The PSCs photodetector demonstrated remarkable responsivity of 11.77 and 7.62×1011 detectivity at 532 nm wavelength. Photocurrent measurements were performed using lasers with 532 nm and 376 nm wavelengths. Under bias voltage applied, the 532 nm laser generated a maximum current of 113 µA, demonstrating superior performance compared to reported photodetectors based on PCSs and perovskite thin films. Collectively, this work opens up a new avenue for enhanced photosensitive photodetectors based on PSCs.

From a wider perspective, the functioning of perovskite-based optoelectronic devices such as solar cells, light-emitting diodes, transistors, and sensors is hugely dependent on the material fabrication of a perovskite active layer, integrating this active layeFrom a wider perspective, the functioning of perovskite-based optoelectronic devices such as solar cells, light-emitting diodes, transistors, and sensors is hugely dependent on the material fabrication of a perovskite active layer, integrating this active layer in the appropriate device architecture and optimizing the device performance by altering various components. An in-depth understanding of the structure-property correlation is, therefore, a key factor for the development of this technology, particularly for industrial large-scale applications. This study aims to comprehend the effect of the material fabrication modifications done at a macroscale, providing insights into the microscale charge-carrier dynamics. Micrograins larger than 100 mu m were achieved for the poly(methyl methacrylate) (PMMA)-incorporated triple-cation perovskite precursor with compact film morphology without any antisolvent treatment. A detailed investigation of the crystallization dynamics is strived for. Enhancement in the radiative recombination lifetime from 0.88 mu s (for the pristine FAMACs film) to 1.45 mu s for the FAMACs film through PMMA incorporation, devoid of any antisolvent treatment, was achieved. Additionally, we appraised our microstructural findings of the photoactive layer against the operating conditions in a device by means of transient photocurrent measurements, aiming for a deeper understanding of the polymer-in-perovskite approach for precursor development.r in the appropriate device architecture and optimizing the device performance by altering various components. An in-depth understanding of the structure-property correlation is, therefore, a key factor for the development of this technology, particularly for industrial large-scale applications. This study aims to comprehend the effect of the material fabrication modifications done at a macroscale, providing insights into the microscale charge-carrier dynamics. Micrograins larger than 100 mu m were achieved for the poly(methyl methacrylate) (PMMA)-incorporated triple-cation perovskite precursor with compact film morphology without any antisolvent treatment. A detailed investigation of the crystallization dynamics is strived for. Enhancement in the radiative recombination lifetime from 0.88 mu s (for the pristine FAMACs film) to 1.45 mu s for the FAMACs film through PMMA incorporation, devoid of any antisolvent treatment, was achieved. Additionally, we appraised our microstructural findings of the photoactive layer against the operating conditions in a device by means of transient photocurrent measurements, aiming for a deeper understanding of the polymer-in-perovskite approach for precursor development.

The formamidinium–cesium (FA–Cs) alloyed metal halide perovskites demonstrate superior photovoltaics device stability; however, alloying at lower Cs concentrations ( ≤ 5%) undergoes complex intermediate phase transitions that disrupt morphological and structural properties. Herein, an intermediate ion‐complex method in a bid is attempted to achieve a near‐optimal energy bandgap of 1.52 eV for α‐FAPbI 3 perovskite (alloyed with 5% Cs + cation). Upon incorporation of judicious amount of smaller and more volatile ions (such as Cl − /Br − and methylammonium [MA] + /Cs + ) into the host FAPbI 3 system, these ions are observed to persist in the “transitional‐phase” and “stimulate” the formation of α‐phase. Consequently, using X‐ray and photoluminescence quantum efficiency measurements, the formation of a (110)‐plane‐oriented high‐quality FA 0.95 Cs 0.05 PbI 3 perovskite thin film with significantly reduced nonradiative recombination is confirmed. An area of 25 mm 2 yields a power conversion efficiency (PCE) of 20.21% and a stabilized power output of 19.82%, leveraging open‐circuit voltage of 90.4% of that Shockley–Queisser limit. The devices sustain over 1000 h without any PCE degradation.

In this study, we are able to fine tune I-rich (AX-rich, such as CH 3 NH 3 I) or I-poor (Pb-rich) growth conditions, which allowing us to deposit highly crystalline “phase-pure” 1.53eV bandgap α-FA 0.95 Cs 0.05 PbI 3 composition.

Engineered 3D perovskite materials are promising candidates for high-efficiency solar cells, having already exceeded Copper indium gallium selenide (CIGS) and Cadmiun Telluride (CdTe) based single-junction cells and trailing only GaAs and Si. Nevertheless, their external luminescence quantum efficiency is modest (<5%) owing to high defect density, which plays an important role in charge trapping and recombination mechanisms for photogenerated carriers. Here, we review and attempt to formulate the rationale for possible types of defect formation and origin of defect core structure that largely deteriorate the 'optoelectronic quality' of perovskite materials and devices. The impact of these imperfections, which range from native 'point defects' to 'higher dimensional defects,' on solar cell efficiency is summarized and investigated. We observed that optoelectronic properties are limited at amorphous grain boundary fusion and transcend at heterojunctions, owing to 'microstructure' related defects. We highlight the intruding effects of 'defect migration' as it imposes unfavorable band alignment, interfacial chemical reactions, material phase separation, and J-V hysteresis. The ambiguous disparity in point defects behavior either at bulk or interface, and stoichiometric adjustment induced–tunned defect formation energies, are analyzed too. Our study emphasizes origin of distinct defects in perovskite and prominence of the acute need to advance the consensus in this exigent challenge.

Antimony Sulfide (Sb2S3) is intriguing wide bandgap photovoltaic (PV) material, having great potential for next generation PV devices. The record power conversion efficiency (PCE) for Sb2S3 solar cells is 8.00%, far from its Schockley-Quiser (SQ) limit of 28.64%. Such mediocre performance is mainly attributed to severe interface-induced recombination losses, stemming from mismatched energy-level alignment, and defects at the interfaces. In this work, rational designing, and simulation of Sb2S3 solar cells was performed using solar cell and capacitance (SCAPS). Band offset optimization endorse Zn(O0.3S0.7) and CuSCN as the optimal electron and hole transport layer (ETL and HTL), respectively. The near ideal Zn(O0.3S0.7)/Sb2S3 interface inhibits the detrimental (interface induced) non-radiative losses, leading to substantial improvement in all the device parameters. Simulation results predict spectacular PCE of 13.88% in regular (n−i−p), and 15.89% in HTL-free Sb2S3 solar cells. This work provides genuine recommendations for the fabrication of cost-competitive, eco-friendly, and high PCE-Sb2S3 solar cells.

Low frequency Capacitance-voltage (C-V) measurements have been employed to investigate the effect of thickness variation of poly (3-hexylthiophene (P3HT) and fullerene [6,6],-phenyl-C61-butyric acid methyl ester (PCBM) based Bulk Heterojunction (BHJ) photo absorbing layer in inverted organic solar cell (OSC) configuration, ITO|ZnO|P3HT:PCBM|MoO3|Ag and are corelated with different recombination mechanisms. The normalized capacitance (CgeomC ) with voltage curves at different P3HT: PCBM blend thicknesses such as 130, 100, 80 and 70 nm demonstrate an increase in peak height with thickness as well as the presence of negative capacitance (NC) beyond peak voltage for higher thicknesses. To understand both peak height variation and the occurrence of NC, a defect sensitive simulation study has been performed by employing the radiative and non radiative recombination processes. Based on the analysis of simulation results we confirm the role of Langevin bimolecular recombination rate in determining the peak height with thickness; however, the presence of NC in CV curves can be understood through a competition between the Langevin bimolecular, and trap assisted recombination rates. Study confirms that peak height reduces due to increase in the rate of Langevin bimolecular recombination, whilst the trap assisted recombination resurges the NC beyond peak voltage. Later, the utilities of D-D based C2 1 3 simulation data at different thicknesses emphasizing the strength of this approach to characterize threshold voltage of organic diodes. vs V analysis to calculate built-in voltage (Vbi) have been performed for the experimental and

Despite the good thermal stability and suitable band gap witnessed in fully inorganic CsPbI3 perovskites, their use in photovoltaic devices is limited due to the lack of long-term phase stability in an ambient environment. Therefore, we demonstrate an effective way of improving long-term ambient and thermal stability along with enhancement in the optoelectronic properties of CsPbI3 thin films. Here, we have shown that the incorporation of Mg and tris(2-aminoethyl)amine (TAEA) in CsPbI3 results in a tremendous increase in thermal as well as ambient stability. It is noted that the presence of both TAEA and Mg is critical for the stabilization of the photoactive black phase of CsPbI3. The TAEA-containing CsPb1-x Mg (x) I-3 film is found to be stable for more than 7 months when exposed to continuous heat at 85 ? in an ambient N2 atmosphere. The optimized CsPb0.85Mg0.15I3 film containing TAEA is detected to showcase the superior optoelectronic properties along with greatly enhanced ambient stability of more than 20 days in RH & SIM;60-70%.

The impact of Tris(2-aminoethyl)amine on enhancing the optoelectronic properties and long-term ambient and thermal stability of FA 0.83 Cs 0.17 Pb(I 0.90 Br 0.10 ) 3 perovskite is deeply investigated.

The growth of FA-based mixed halide perovskite single-crystal via the ITC method has been investigated and characterized to detect its photosensitive properties. The photophysical, responsivity and detectivity also has been investigated.

Fully inorganic CsPbI3 perovskite has been widely explored as an alternative light-harvesting material owing to its superior thermal stability over the organic-inorganic halide perovskite and the suitable band gap. However, stabilization of the photoactive CsPbI3 phase at room temperature (RT) remains the biggest challenge. The photoactive alpha-CsPbI3 which requires high-temperature synthesis (above 320 degrees C) transforms into the photoactive gamma-CsPbI3 at RT and on exposure to ambient rapidly transforms into the non-photoactive delta-CsPbI3. Herein, we investigate the effect of incorporating Mg2+ in the CsPbI3 lattice. It has been found that the photoactive gamma-phase of CsPbI3 can be stabilized for more than 167 days at RT in a nitrogen atmosphere by incorporating Mg2+ inside the lattice. Incorporating Mg2+ inside the lattice of CsPbI3 has led to enhanced optoelectronic properties along with enhanced phase and thermal stability.

Their unique quasi one-dimensional (Q1D) crystal structure and rapid power conversion efficiency (PCE) evolution evoke tremendous scientific and technological interest in antimony chalcogenide (Sb2X3, X = S, Se, or SxSe1-x) photovoltaics (PVs). Solution processability, strong photon harvesting, readily tunable optoelectronic properties, exceptional physicochemical stability, nontoxicity, and earth-abundance are their key features, endorsing Sb2X3 as next-generation PVs. Benign, self-healing grain boundaries and defect-tolerance add to their merits, empowering Sb2X3 films to act like pseudo-single crystals. These semiconductors are born for flexible PVs, as their Q1D crystal structures aid ultrahigh flexibility and bending tolerance. Sb2X3 solar cells are efficient in recycling indoor and ambient light; thus, they are promising as indoor PVs (IPVs). Sb2X3 PVs exhibit potential to simultaneously solve the stability and toxicity issues faced by lead halide perovskite PVs and the cost issues faced by mainstream silicon PVs. Presently, a record certified PCE of 10.7% has been demonstrated by Sb2X3 solar cells; thus, they are emerging as a promising low-cost alternative to the commercially available PV technologies. This review presents a unique perspective of the fundamentals, recent breakthroughs, challenges, and futuristic developments in this field, offering a fundamental guideline for the rational engineering, design, and fabrication of high-PCE Sb2X3 solar cells. This review highlights Sb2X3 based, large area, tandem, and flexible solar cells and explores the commercial viability of this technology from generic power production to niche markets.

This work investigates the synthesis of Cesium (Cs) based all-inorganic (CsPbBr3) perovskite single crystals (PSCs) at low temperatures (45 °C) for application in photosensitive devices.

Background & objectives:The tribal population in India is considered as one of the vulnerable groups with respect to their achievements in health and other developmental issues. In this context, this mapping review attempted to understand the health profile of the Tharu tribal community residing in the northern State of Uttar Pradesh, India through literature mining. Tharu tribe is one of the indigenous groups living in the Terai plain on the Indo-Nepal border. In 1967, this tribe was documented as a Scheduled Tribe by the Government of India. The present review aimed to map the health-seeking behaviour of the Tharu population and review other factors pertaining to their health such as socioeconomic, developmental, employment, education, etc. Methods:Online data search was carried out on PubMed and Google Scholar using search terms 'Tharu' AND 'India'. In addition, official reports avaibale in public domain and grey literature was also searched. Results:Twenty seven studies including reviews, articles, books/book chapters were evaluated along with 13 reports (including reports from government organizations and grey literature) were retrieved and analyzed. Of the 27 published reports, 16 were found relevant to Tharu tribe in India. A total of 29 (16 articles + 13 reports ) were included in this review. Interpretation & Conclusions:This mapping review highights the health seeking behaviour of the Tharu tribe in India that can help inform future interventions to improve the health status of the Tharu tribe as well as other aspects of their development.

Perovskite photovoltaics advance rapidly, but questions remain regarding point defects: while experiments have detected the presence of electrically active defects no experimentally confirmed microscopic identifications have been reported. Here we identify lead monovacancy (V Pb ) defects in MAPbI 3 (MA = CH 3 NH 3 + ) using positron annihilation lifetime spectroscopy with the aid of density functional theory. Experiments on thin film and single crystal samples all exhibited dominant positron trapping to lead vacancy defects, and a minimum defect density of 3 × 10 15 cm −3 was determined. There was also evidence of trapping at the vacancy complex (V_PbV_I)^- in a minority of samples, but no trapping to MA-ion vacancies was observed. Our experimental results support the predictions of other first-principles studies that deep level, hole trapping, V_Pb^2- , point defects are one of the most stable defects in MAPbI 3 . This direct detection and identification of a deep level native defect in a halide perovskite, at technologically relevant concentrations, will enable further investigation of defect driven mechanisms.

Sequential deposition route is widely investigated in fabricating perovskite thin films for state‐of‐the‐art perovskite photovoltaics. However, concerns such as lower morphological control, phase purity, and remnant unreacted salts methylammonium iodide (MAI and PbI2) are raised, which can significantly deteriorate optoelectronic properties, hence the operational durability of the devices. Herein, a facile two‐step method to prepare high‐quality perovskite thin films with reproducibility is reported, as‐spun PbI2 is annealed at varying thermal input under controlled rate, and a trend in converted perovskite film properties is noted. Specifically, PbI2 thin film annealed at 200 °CC results in 20x intensified crystallinity with pinholes free and a subsequent reduction in the crystal microstrain. In addition, it provides higher surface roughness to load more MAI [in iso‐propyl alcohol (IPA)]; therefore, a higher perovskite conversion is achieved. This method enables a significant efficiency enhancement in the treated sample (Pero@PbI2‐200 °C) as compared with controlled film; it retains around 90% initial efficiency after 384 h of ambient exposure. Furthermore, a facile intermediate solvent treatment method to gain the complete conversion of PbI2 into perovskite is also reported. This study highlights the importance of morphological control in governing optoelectronic properties, hence the efficiency and stability of perovskite solar cells.

A two-step deposition method has been a promising technique to fabricate perovskite optoelectronic devices because of the advantages of fabrication robustness and control over morphology. However, ...

Defects formed during the device processing acts as recombination centers and shows adverse effects on the photovoltaic performance of the organic solar cells (OSCs). In this manuscript, a study on the effect of defect states on the characteristics of bulk heterojunction (BHJ) solar cells, consisted of unannealed or thermally annealed active layer (ActL) of PTB7:PC71BM blend, have been performed by using the illumination intensity-dependent current-voltage and frequency dependent impedance spectroscopy measurements. Our results indicate that the photovoltaic performance of devices based on annealed ActL is superior than the bench dried ActL due to thermal annealing induced improvement in the thin film morphology. The measured low-frequency capacitance-voltage (C–V) characteristics under varying illumination intensities show strong dependency on the photoexcitation however, the change in the C–V characteristics is found to be quite different for unannealed and annealed devices. The C–V characteristics are analyzed using the drift-diffusion model to extract the effective built-in voltage (Vbi) and the surface photovoltage as a function of illumination intensity. The capacitance-frequency characteristics under illumination reveal that the change in the capacitance is associated with the photo-induced carrier occupation in the intermixture donor-acceptor phases, which act as the defect states in such devices. Further, it is modeled to quantify the defect states and to demonstrate the importance of thermal annealing for improving the OSCs device performance.

Hybrid organic-inorganic lead halide perovskites have shown excellent photovoltaic performance due to their remarkable unique optoelectronic properties in their polycrystalline thin film; however their performance is limited due to the presence of grain boundaries. It is noted that perovskite single crystals have larger domains and hence significantly low trap density with higher diffusion length. In the present manuscript, we report the anti-solvent modified inverse-temperature-crystallization (ITC) approach to synthesis perovskite (MAPbI(3)) single crystals (1 cm in size) of superior opto-electronic quality at room temperature (30 degrees C/RT). To accomplish this first we have developed an understanding on the role of various growth parameters such as temperatures and precursor compositions (amount of anti-solvent and solution molarity) during crystal growth via ITC process in attaining the suitable condition for crystal. Careful control over the amount of anti-solvent and solution molarity helps in realizing the crystal growth even at very high temperatures (140 degrees C) as well as at room temperature. Specifically, the quality of RT crystals was compared with control (60 degrees C) crystals and high temperature (140 degrees C/HT) crystals using XRD, vis-NIR absorbance, photoluminescence (PL) and scanning electron microscope (SEM) analysis. The RT single crystals are compared with the control and HT single crystal.

In this study, newly designed perylene diimide based polymers P1 and P2 were synthesized and were used as hole transporting materials in place of the more common spiro-OMeTAD in perovskite solar cells. The co-polymers P1-P2 were synthesized by Suzuki and direct arylation polymerizations of 2,9-bis(7-bromo-9,9-dioctyl-9H-fluoren-2-yl)anthra[2,1,9-def:6,5,10-d’e’f’]diisoquinoline-1,3,8,10(2H,9H)-tetrone M1 with 5,11-bis(2-hexyldecyl)-3,9-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,11-dihydoindolo[3,2-b]carbazole M2 and 3-octylthiophene M3, respectively. P1 and P2 exhibit broad absorption spectra in thin film and solution with the absorption extending from the ultraviolet to visible and near infrared region of the solar spectrum. The water contact angles of P1-P2 were determined to be 100.8° and 122.9°, respectively, showing good hydrophobicity for the synthesized copolymers. Both polymers show steady state photoluminescence quenching when blended with perovskite. Perovskite solar cell devices fabricated using P1-P2 in place of spiro-OMeTAD show power conversion efficiencies of 13.02% and 10.74%, respectively and manifest the potential of this class of materials as promising alternatives to conventionally used spiro-OMeTAD.