Magnetic and optical properties of perovskite-graphene nanocomposites LaFeO₃-rGO: Experimental and DFT calculations

We present an experimental and theoretical study of the perovskite-graphene nanocomposites LaFeO3 – rGO, where we demonstrate a easy way to prepare this compound using citrate auto-compulsion method, starting from corresponding metal nitrate and graphene oxide solution. The Hummer’s method was used to prepare graphene oxide by chemical exfoliation of graphite. The structural characterization has been performed using XRD, FT-IR and scanning electron microscope (SEM) to analyze the morphology of the sample, FT-IR, whereas the magnetic properties has been studied using VSM measurements. Furthermore, ab-initio calculations has been performed based on the Density Functional Theory (DFT), where for a better description of the electronic and magnetic properties, the Hubbard correction was considered over the General Gradient Approximation (GGA + U).Facultad de Ciencias ExactasInstituto de Física de Líquidos y Sistemas Biológico

Magnetic and optical properties of perovskite-graphene nanocomposites LaFeO3-rGO: Experimental and DFT calculations

We present an experimental and theoretical study of the perovskite-graphene nanocomposites LaFeO3 – rGO, where we demonstrate a easy way to prepare this compound using citrate auto-compulsion method, starting from corresponding metal nitrate and graphene oxide solution. The Hummer’s method was used to prepare graphene oxide by chemical exfoliation of graphite. The structural characterization has been performed using XRD, FT-IR and scanning electron microscope (SEM) to analyze the morphology of the sample, FT-IR, whereas the magnetic properties has been studied using VSM measurements. Furthermore, ab-initio calculations has been performed based on the Density Functional Theory (DFT), where for a better description of the electronic and magnetic properties, the Hubbard correction was considered over the General Gradient Approximation (GGA + U).Fil: Abdel Aal, Seham K.. Cairo University; EgiptoFil: Aly, Abeer E.. El Salam Higher Institution for Engineering and Technology; EgiptoFil: Medina Chanduvi, Hugo Harold. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Gil Rebaza, Arles Víctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Atteia, E.. Physics Department Faculty Of Science, Cairo University; EgiptoFil: Shankar, A.. Kurseong College; Indi

Nanoarchitectonics of lead-free 2D cobalt-based diammonium hybrid for perovskites solar cell applications

This study presents the fabrication of new, non-toxic perovskite solar cells using 2D cobalt-based perovskite materials. Three cobalt-based Organic–inorganic 2D hybrid perovskite (HOIP) materials were synthesized, and their photovoltaic properties were evaluated: [NH3(CH2)nNH3]CoCl4 (n = 4, 9) and [NH3(CH2)7NH3]CoBr2Cl2. These materials encompassed varying organic chain lengths (short, medium, and long) as well as chloride and mixed chloride/bromide anions. The molecular structure was examined to establish correlations with the structural and optical properties. The synthesized compounds exhibited visible light absorption, with varying bandgap energy from 1.7 eV to 2.7 eV. To test the application of Co-based perovskites, two distinct solar cell architectures were employed. The first architecture, denoted as Architecture 1, consisted of the following layers: Glass/FTO/c-TiO2/m-TiO2/ZrO2/2D Co-based HOIP/C-electrode. The second architecture, referred to as Architecture 2, utilized a planar heterojunction structure deposited with different transport layers for electrons and holes. Specifically, it comprised the layers: Glass/ITO/SnO2/2D Co-based HOIP/Spiro-OMeTAD/Au. Among these architectures, Architecture 2 exhibited notable performance. It achieved a maximal open circuit voltage (Voc) of 0.93 V, and current density (Jsc) of 0.24 mA/cm2, with efficiency of 0.47%, and a fill factor (FF) of 78%. These findings demonstrate the effectiveness of adjusting the perovskite material composition and controlling the deposition conditions in raising solar cell efficiency

Nanoarchitectonics of lead-free 2D cobalt-based diammonium hybrid for perovskites solar cell applications

This study presents the fabrication of new, non-toxic perovskite solar cells using 2D cobalt-based perovskite materials. Three cobalt-based Organic–inorganic 2D hybrid perovskite (HOIP) materials were synthesized, and their photovoltaic properties were evaluated: [NH3(CH2)nNH3]CoCl4 (n = 4, 9) and [NH3(CH2)7NH3]CoBr2Cl2. These materials encompassed varying organic chain lengths (short, medium, and long) as well as chloride and mixed chloride/bromide anions. The molecular structure was examined to establish correlations with the structural and optical properties. The synthesized compounds exhibited visible light absorption, with varying bandgap energy from 1.7 eV to 2.7 eV. To test the application of Co-based perovskites, two distinct solar cell architectures were employed. The first architecture, denoted as Architecture 1, consisted of the following layers: Glass/FTO/c-TiO2/m-TiO2/ZrO2/2D Co-based HOIP/C-electrode. The second architecture, referred to as Architecture 2, utilized a planar heterojunction structure deposited with different transport layers for electrons and holes. Specifically, it comprised the layers: Glass/ITO/SnO2/2D Co-based HOIP/Spiro-OMeTAD/Au. Among these architectures, Architecture 2 exhibited notable performance. It achieved a maximal open circuit voltage (Voc) of 0.93 V, and current density (Jsc) of 0.24 mA/cm2, with efficiency of 0.47%, and a fill factor (FF) of 78%. These findings demonstrate the effectiveness of adjusting the perovskite material composition and controlling the deposition conditions in raising solar cell efficiency