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1.
Phys Chem Chem Phys ; 25(42): 29050-29060, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37860862

RESUMO

This study investigates the incorporation of Ba2+ at a low concentration into CsPbI2Br, resulting in the formation of mixed CsPb1-xBaxI2Br perovskite films. Photovoltaic devices utilizing these Ba-doped CsPbI2Br (Ba-CsPbI2Br) perovskite films achieved a higher stabilized power conversion efficiency of 14.07% compared to 11.60% for pure CsPbI2Br films. First-principles density functional theory calculations indicate that the improved device performance can be attributed to the efficient transport of conduction electrons across the interface between Ba-CsPbI2Br and the TiO2 electron transporting layer (ETL). The Ba-CsPbI2Br/TiO2 interface exhibits a type-II staggered band alignment with a smaller conduction band offset (CBO) of 0.25 eV, in contrast to the CsPbI2Br/TiO2 interface with a CBO of 0.48 eV. The reduced CBO at the Ba-CsPbI2Br/TiO2 interface diminishes the barrier for conduction electrons to transfer from the Ba-CsPbI2Br layer to the TiO2 layer, facilitating efficient charge transport.

2.
Membranes (Basel) ; 13(9)2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37755170

RESUMO

Layered double hydroxides (LDHs) have gained vast importance as an electrocatalyst for water electrolysis to produce carbon-neutral and clean hydrogen energy. In this work, we demonstrated the fabrication of nano-flake-like NiMn LDH thin film electrodes onto porous membrane-like Ni-foam by using a simple and cost-effective electrodeposition method for oxygen evolution reaction (OER). Various Ni1-xMnx LDH (where x = 0.15, 0.25, 0.35, 0.50 and 0.75) thin film electrodes are utilized to achieve the optimal catalyst for an efficient and sustainable OER process. The various composition-dependent surface morphologies and porous-membrane-like structure provided the high electrochemical surface area along with abundant active sites facilitating the OER. The optimized catalyst referred to as Ni0.65Mn0.35 showed excellent OER properties with an ultralow overpotential of 253 mV at a current density of 50 mAcm-2, which outperforms other state-of-the art catalysts reported in the literature. The relatively low Tafel slope of 130 mV dec-1 indicates faster and more favorable reaction kinetics for OER. Moreover, Ni0.65Mn0.35 exhibits excellent durability over continuous operation of 20 h, indicating the great sustainability of the catalyst in an alkaline medium. This study provides knowledge for the fabrication and optimization of the OER catalyst electrode for water electrolysis.

3.
RSC Adv ; 13(31): 21283-21295, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37456552

RESUMO

This study shows a simplistic, efficient procedure to synthesize TiO2-MoO3-BMIMBr nanocomposites. Powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy have all been used to completely analyse the materials. The detection of acetaminophen (AC) has been examined at a modified glassy carbon electrode with TiO2-MoO3-BMIMBr nanocomposites. Moreover, the electrochemical behavior of the nanocomposite modified electrode has been studied by cyclic voltammetry (CV), differential pulse voltammetry (DPV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The linear response of AC was observed in the range 8.26-124.03 nM. The sensitivity and detection limits (S/N = 3) were found to be 1.16 µA L mol-1 cm-2 and 11.54 nM by CV and 24 µA L mol-1 cm-2 and 8.16 nM by DPV respectively.

4.
Materials (Basel) ; 16(3)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36769895

RESUMO

In the present investigation, a one-step hydrothermal approach is proposed to synthesize Li+, Rb+, and In3+intercalated PW12O40 (PTA) thin films. The photoelectrochemical performance of the deposited Li3PW12O40 (Li-PTA), Rb3PW12O40 (Rb-PTA), and In3PW12O40 (In-PTA) photocathodes were investigated using a two-electrode cell configuration of FTO/Li3PW12O40/(0.1 M I-/I3-)aq./Graphite. The energy band gaps of 2.24, 2.11, and 2.13 eV were observed for the Li-PTA, Rb-PTA, and In-PTA films, respectively, as a function of Li+, Rb+, and In3+. The evolution of the spinal cubic crystal structure with increased crystallite size was observed for Rb+ intercalation within the PTA Keggin structure, which was confirmed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) revealed a modification in the surface morphology from a rod-like structure to a densely packed, uniform, and interconnected microsphere to small and large-sized microspheres for Li-PTA, Rb-PTA, and In-PTA, respectively. Compositional studies confirmed that the composing elements of Li, Rb, In, P, W, and O ions are well in accordance with their arrangement for Li+, Rb+, In3+, P5+, W6+, and O2- valence states. Furthermore, the J-V performance of the deposited photocathode shows power conversion efficiencies (PCE) of 1.25%, 3.03%, and 1.62%, as a function of the incorporation of Li+, Rb+, and In3+ ions. This work offers a one-step hydrothermal approach that is a prominent way to develop Li+, Rb+, and In3+ ions intercalated PTA, i.e., Li3PW12O40, Rb3PW12O40, and In3PW12O40 photocathodes for competent solar energy harvesting.

5.
RSC Adv ; 12(50): 32249-32261, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36425716

RESUMO

This work reports the synthesis of Mn-doped ZnSnO3 microspheres (Zn1-x Mn x SnO3) using a simple co-precipitation method with (x = 0 to 0.15) and characterized for structural, morphological, surface area, and sensing properties. X-ray diffraction (XRD) analysis revealed the face-centered cubic structure of Mn-doped ZnSnO3 samples. Brunauer-Emmett-Teller (BET) analysis demonstrated the variation in surface area from 15.229 m2 g-1 to 42.999 m2 g-1 with x = 0 to 0.15 in Zn1-x Mn x SnO3. XPS indicates the change in the defect levels by Mn doping, which plays a crucial role in chemical sensors. Indeed a significant increase (≈311.37%) in CO gas sensing response was observed in the x = 0.10 sample compared to pure ZnSnO3 with a simultaneous reduction in operating temperature from 250 to 200 °C. Moreover, remarkable enhancements in response/recovery times (≈6.6/34.1 s) were obtained in the x = 0.10 sample. The Mn-doped ZnSnO3 could be a promising candidate for CO gas sensing devices used for maintaining air quality.

6.
Polymers (Basel) ; 14(17)2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36080646

RESUMO

A low-cost and effective flame retarding expanded polystyrene (EPS) foam was prepared herein by using a hybrid flame retardant (HFR) system, and the influence of gypsum was studied. The surface morphology and flame retardant properties of the synthesized flame retardant EPS were characterized using scanning electron microscopy (SEM) and cone calorimetry testing (CCT). The SEM micrographs revealed the uniform coating of the gypsum-based HFR on the EPS microspheres. The CCT and thermal conductivity study demonstrated that the incorporation of gypsum greatly decreases the peak heat release rate (PHRR) and total heat release (THR) of the flame retarding EPS samples with acceptable thermal insulation performance. The EPS/HFR with a uniform coating and the optimum amount of gypsum provides excellent flame retardant performance, with a THR of 8 MJ/m2, a PHRR of 53.1 kW/m2, and a fire growth rate (FIGRA) of 1682.95 W/m2s. However, an excessive amount of gypsum weakens the flame retardant performance. The CCT results demonstrate that a moderate gypsum content in the EPS/HFR sample provides appropriate flame retarding properties to meet the fire safety standards.

7.
Adv Mater ; 34(29): e2203204, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35581144

RESUMO

Realizing photoactive and thermodynamically stable all-inorganic perovskite solar cells (PSCs) remains a challenging task within halide perovskite photovoltaic (PV) research. Here, a dual strategy for realizing efficient inorganic mixed halide perovskite PV devices based on a terbium-doped solar absorber, that is, CsPb1- x Tbx I2 Br, is reported, which undertakes a bulk and surface passivation treatment in the form of CsPb1- x Tbx I2 Br quantum dots, to maintain a photoactive γ-phase under ambient conditions and with significantly improved operational stability. Devices fabricated from these air-processed perovskite thin films exhibit an air-stable power conversion efficiency (PCE) that reaches 17.51% (small-area devices) with negligible hysteresis and maintains >90% of the initial efficiency when operating for 600 h under harsh environmental conditions, stemming from the combined effects of the dual-protection strategy. This approach is further examined within large-area PSC modules (19.8 cm2 active area) to realize 10.94% PCE and >30 days ambient stability, as well as within low-bandgap γ-CsPb0.95 Tb0.05 I2.5 Br0.5 (Eg  = 1.73 eV) materials, yielding 19.01% (18.43% certified) PCE.

8.
ACS Appl Mater Interfaces ; 14(22): 25576-25583, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35621172

RESUMO

Obtaining good-quality perovskite thin films is a fundamental facet that contributes to efficient inorganic perovskite solar cells. Herein, we successfully deposited ethylammonium bromide (EABr) additive-assisted high quality γ-CsPbI2Br perovskite films under ambient conditions. Detailed morphological, structural, optical, charge transport, photovoltaic performance, and stability properties have been studied. It is observed that the EABr additive helps to retard the crystal growth of perovskite films to produce a highly crystalline perovskite film with microsized grains (>1 µm) and with reduced grain boundaries. The fabricated devices based on an optimum amount of EABr (4 mg mL-1) exhibited the highest 14.47 % power conversion efficiency. Moreover, the EABr-4 mg mL-1-assisted γ-CsPbI2Br-based devices achieved a high thermal long-term stability and maintained ∼75% of their initial efficiency over 180 h at 85 °C thermal stress under ambient conditions (relative humidity: ∼35%) without encapsulation. This additive-assisted method suggests a new pathway to achieve high-quality perovskite films with a stabilized photoactive black phase and efficient devices.

9.
Materials (Basel) ; 14(21)2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34771806

RESUMO

The one-step hydrothermal method was used to synthesize Sn-doped TiO2 (Sn-TiO2) thin films, in which the variation in Sn content ranged from 0 to 7-wt % and, further, its influence on the performance of a dye-sensitized solar cell (DSSC) photoanode was studied. The deposited samples were analyzed by X-ray diffraction (XRD) and Raman spectroscopy, which confirmed the existence of the rutile phase of the synthesized samples with crystallite size ranges in between 20.1 to 22.3 nm. In addition, the bare and Sn-TiO2 thin films showed nanorod morphology. A reduction in the optical band gap from 2.78 to 2.62 eV was observed with increasing Sn content. The X-ray photoelectron spectroscopy (XPS) analysis confirmed Sn4+ was successfully replaced at the Ti4+ site. The 3-wt % Sn-TiO2 based DSSC showed the optimum efficiency of 4.01%, which was superior to 0.87% of bare and other doping concentrations of Sn-TiO2 based DSSCs. The present work reflects Sn-TiO2 as an advancing material with excellent capabilities, which can be used in photovoltaic energy conversion devices.

10.
Polymers (Basel) ; 13(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34451203

RESUMO

The compatibility and coating ratio between flame retardant materials and expanded polystyrene (EPS) foam is a major impediment to achieving satisfactory flame retardant performance. In this study, we prepared a water-based intumescent flame retardant system and methylene diphenyl diisocyanate (MDI)-coated expandable polystyrene microspheres by a simple coating approach. We investigated the compatibility, coating ratio, and fire performance of EPS- and MDI-coated EPS foam using a water-based intumescent flame retardant system. The microscopic study revealed that the water-based intumescent flame retardant materials were successfully incorporated with and without MDI-coated EPS microspheres. The cone calorimeter tests (CCTs) of the MDI-coated EPS containing water-based intumescent flame retardant materials exhibited better flame retardant performance with a lower total heat release (THR) 7.3 MJ/m2, peak heat release rate (PHRR) 57.6 kW/m2, fire growth rate (FIGRA) 2027.067 W/m2.s, and total smoke production (TSP) 0.133 m2. Our results demonstrated that the MDI-coated EPS containing water-based intumescent flame retardant materials achieved flame retarding properties as per fire safety standards.

11.
Polymers (Basel) ; 13(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199577

RESUMO

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.

12.
ACS Omega ; 6(26): 17071-17085, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34250364

RESUMO

Nanostructured titanium dioxide (TiO2) has a potential platform for the removal of organic contaminants, but it has some limitations. To overcome these limitations, we devised a promising strategy in the present work, the heterostructures of TiO2 sensitized by molybdenum disulfide (MoS2) nanoflowers synthesized by the mechanochemical route and utilized as an efficient photocatalyst for methyl orange (MO) degradation. The surface of TiO2 sensitized by MoS2 was comprehensively characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence spectroscopy (PL), Brunauer-Emmett-Teller (BET) surface area, and thermogravimetric analysis (TGA). From XRD results, the optimized MoS2-TiO2 (5.0 wt %) nanocomposite showcases the lowest crystallite size of 14.79 nm than pristine TiO2 (20 nm). The FT-IR and XPS analyses of the MoS2-TiO2 nanocomposite exhibit the strong interaction between MoS2 and TiO2. The photocatalytic results show that sensitization of TiO2 by MoS2 drastically enhanced the photocatalytic activity of pristine TiO2. According to the obtained results, the optimal amount of MoS2 loading was assumed to be 5.0 wt %, which exhibited a 21% increment of MO photodegradation efficiency compared to pristine TiO2 under UV-vis light. The outline of the overall study describes the superior photocatalytic performance of 5.0 wt % MoS2-TiO2 nanocomposite which is ascribed to the delayed recombination by efficient charge transfer, high surface area, and elevated surface oxygen vacancies. The context of the obtained results designates that the sensitization of TiO2 with MoS2 is a very efficient nanomaterial for photocatalytic applications.

13.
Polymers (Basel) ; 13(10)2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34065575

RESUMO

Sulfonated poly(styrene-ethylene-butylene-styrene) copolymer (S-SEBS) was prepared as an anion exchange membrane using the casting method. The prepared S-SEBS was further modified with sulfonic acid groups and grafted with maleic anhydride (MA) to improve the ionic conducting properties. The prepared MA-grafted S-SEBS (S-SEBS-g-MA) membranes were characterized by Fourier transform infrared red (FT-IR) spectroscopy and dynamic modulus analysis (DMA). The morphology of the S-SEBS and S-SEBS-g-MA was investigated using atomic force microscopy (AFM) analysis. The modified membranes formed ionic channels by means of association with the sulfonate group and carboxyl group in the SEBS. The electrochemical properties of the modified SEBS membranes, such as water uptake capability, impedance spectroscopy, ionic conductivity, and ionic exchange capacity (IEC), were also measured. The electrochemical analysis revealed that the S-SEBS-g-MA anion exchange membrane showed ionic conductivity of 0.25 S/cm at 100% relative humidity, with 72.5% water uptake capacity. Interestingly, we did not observe any changes in their mechanical and chemical properties, which revealed the robustness of the modified SEBS membrane.

14.
ACS Appl Mater Interfaces ; 13(17): 20296-20304, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33877795

RESUMO

Fullerene derivatives with a strong electron-accepting ability play a crucial role in enhancing both the performance and stability of perovskite solar cells (PSCs). However, most of the used fullerene molecules are based on [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), which limits the device performance due to difficulties in preparing high-quality and uniform thin films. Herein, solution-processable azahomofullerene (AHF) derivatives (abbreviated as AHF-1 and AHF-2) are reported as novel and effective electron-transport layers (ETLs) in p-i-n planar PSCs. Compared to the control PCBM ETL-based PSCs, the devices based on AHFs exhibit higher photovoltaic performances, which is attributed to the enhanced charge-transport properties and improved layer morphology leading to a maximum power conversion efficiency (PCE) of 20.21% in the case of the device based on AHF-2 ETL. Besides, due to the preferable energy band alignment with the perovskite layer, reduced trap states, and suppressed charge recombination, the device with AHF-2 ETL exhibits significantly suppressed hysteresis and improved stability under both ambient and thermal conditions.

15.
ACS Energy Lett ; 6(2): 778-788, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33829109

RESUMO

Mixed-halide CsPbI2Br perovskite is promising for efficient and thermally stable all-inorganic solar cells; however, the use of conventional antisolvent methods and additives-based hole-transporting layers (HTLs) currently hampers progress. Here, we have employed hot-air-assisted perovskite deposition in ambient condition to obtain high-quality photoactive CsPbI2Br perovskite films and have extended stable device operation using metal cation doping and dopant-free hole-transporting materials. Density functional theory calculations are used to study the structural and optoelectronic properties of the CsPbI2Br perovskite when it is doped with metal cations Eu2+ and In3+. We experimentally incorporated Eu2+ and In3+ metal ions into CsPbI2Br films and applied dopant-free copper(I) thiocyanate (CuSCN) and poly(3-hexylthiophene) (P3HT)-based materials as low-cost hole transporting layers, leading to record-high power conversion efficiencies of 15.27% and 15.69%, respectively, and a retention of >95% of the initial efficiency over 1600 h at 85 °C thermal stress.

16.
ACS Appl Mater Interfaces ; 12(24): 27176-27183, 2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-32484326

RESUMO

Inorganic cesium lead halide perovskite (CsPbX3) is a promising light-harvesting material to increase the thermal stability and the device performance as compared to the organic-inorganic hybrid counterparts. However, the photoactive stability at ambient conditions is an unresolved issue. Here, we studied the influence of Nb5+ ions' incorporation in the CsPbI2Br perovskite processed at ambient conditions. Our results exhibited that 0.5% Nb-incorporated CsPb1-xNbxI2Br (herein x = 0.005) thin films show excellent uniformity and improved grain size because of the optimum concentration of Nb5+ doping and hot-air flow. The improved grain size and uniform film thickness deliver a superior interface between the CsPb1-xNbxI2Br layer and the hole-transporting material. The fabricated all-inorganic perovskite solar cell (IPVSC) devices exhibited the Nb5+ cation incorporation which enables decreased charge recombination, leading to negligible hysteresis. The champion device produces an open-circuit voltage (VOC) as high as 1.317 V. The IPVSC device containing a CsPb0.995Nb0.005I2Br composition delivers the highest power conversion efficiency of 16.45% under a 100 mW cm-2 illumination and exhibits a negligible efficiency loss over 96 h in ambient conditions.

17.
ACS Appl Mater Interfaces ; 12(7): 8098-8106, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31994862

RESUMO

Perovskite solar cells (PSCs) have experienced outstanding advances in power conversion efficiencies (PCEs) by employing new electron transport layers (ETLs), interface engineering, optimizing perovskite morphology, and improving charge collection efficiency. In this work, we study the role of a new ultrathin interface layer of titanium nitride (TiN) conformally deposited on a mesoporous TiO2 (mp-TiO2) scaffold using the atomic layer deposition method. Our characterization results revealed that the presence of TiN at the ETL/perovskite interface improves the charge collection as well as reduces the interface recombination. We find that the morphology (grain size) and optical properties of the perovskite film deposited on the optimized mp-TiO2/TiN ETL are improved drastically, leading to devices with a maximum PCE of 19.38% and a high open-circuit voltage (Voc) of 1.148 V with negligible hysteresis and improved environmental (∼40% RH) and thermal (80 °C) stabilities.

18.
RSC Adv ; 10(61): 36949-36961, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-35521260

RESUMO

Nickel (Ni2+) ion doped zinc oxide-multi-wall carbon nanotubes (NZC) with different composition ratios of MWCNTs (from 0.01 to 0.1 wt%) are synthesized through an in situ sol-gel method. The synthesized NZC nanocomposites (NCs) are used as electrode materials with glassy carbon electrodes (GCEs) for electrochemical detection of uric acid (UA). The cyclic voltammogram of the representative NZC 0.1 modified GCE (NZC 0.1/GCE) revealed the highest electrochemical sensing activity towards the oxidation of UA at 0.37 V in 0.2 M phosphate buffer solution (PBS) having pH 7.4 ± 0.02. The limit of detection (LOD) and limit of quantification (LOQ) for the NZC 0.1/GCE are determined to be 5.72 nM and 19.00 nM (S/N = 3) respectively, which is the lowest compared to the literature values reported for enzymatic and non-enzymatic detection techniques. The synergistic effect of NZC 0.1 NCs is proposed as one of the factors for the enhanced electrochemical oxidation of UA complemented by the phase, lattice parameters, functional groups, morphology, elemental compositions, types of bonding and specific surface area with pore size ascertained using various techniques. The synthesized NZC 0.1 NCs are further proposed as selective electrode materials for the electrochemical detection of UA as authenticated further by performing interference tests with other metabolites such as ascorbic acid (AA), dopamine (DA) and d-glucose. The optimized electrochemical studies are further adopted for sensing of UA from human excretion samples using NZC 0.1 NCs.

19.
Nanoscale ; 11(45): 21824-21833, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31693036

RESUMO

Quadruple cation-based perovskite solar cells (PVSCs) have crossed the power conversion efficiency (PCE) of 25.2% because of their effective light harvesting ability. The perovskite materials and type of additives play a crucial role in improving the photovoltaic performance and stability. Therefore, here, we demonstrated a simple approach to reduce the grain boundaries and increase the grain size by adding thiourea (TU) as an additive in mixed halide (FAPbI3)0.85(MAPbBr3)0.15, triple cation Cs0.05[(FAPbI3)0.85(MAPbBr3)0.15]0.95 and quadruple Rb0.05{Cs0.05[(FAPbI3)0.85(MAPbBr3)0.15]0.95}0.95 cation perovskite absorbers. Our results indicate that the TU-added perovskite thin films have positive effects on the grain size, which improved up to 2.6 µm for the quadruple cation. Final optimization with the quadruple cation containing TU additive-based PVSC exhibited a 20.92% PCE, which is higher than additive-free PVSCs. Furthermore, the stability of the additive-modified PVSCs is much higher than that of bare films due to their ultra-large grain size with reduced grain boundaries. In addition, our thermal stress results exhibited that the additive-based PVSC devices display better thermal stability of more than ∼100 h at 60 °C without encapsulation.

20.
Nano Lett ; 19(9): 6213-6220, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31369285

RESUMO

Replacement of conventional organic cations by thermally stable inorganic cations in perovskite solar cells (PSCs) is one of the promising approaches to make thermally stable photovoltaics. However, conventional spin-coating and solvent-engineering processes in a controlled inert atmosphere hamper the upscaling. In this study, we demonstrated a dynamic hot-air (DHA) casting process to control the morphology and stability of all-inorganic PSCs which is processed under ambient conditions and free from conventional harmful antisolvents. Furthermore, CsPbI2Br perovskite was doped with barium (Ba2+) alkaline earth metal cations (BaI2:CsPbI2Br). This DHA method facilitates the formation of uniform grain and controlled crystallization that makes stable all-inorganic PSCs which enables an intact black α-phase under ambient conditions. The DHA-processed BaI2:CsPbI2Br perovskite photovoltaics shows the champion power conversion efficiency (PCE) of 14.85% (reverse scan) for a small exposure area of 0.09 cm2 and 13.78% for a large area of 1 × 1 cm2 with excellent reproducibility. Interestingly, the hot-air-processed devices retain >92% of the initial efficiency after 300 h. This DHA method facilitates a wide processing window for upscaling the all-inorganic perovskite photovoltaics.

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