scholarly journals Síntesis, simulación y propiedades ópticas de un resorcinareno portador de quinolinas

2021 ◽  
Vol 9 (Especial2) ◽  
pp. 187-192
Author(s):  
Damaris Castro-Monter ◽  
Ventura Rodríguez-Lugo ◽  
María Isabel Reyes-Valderrama ◽  
Ivana Moggio ◽  
Eduardo Manuel Arias Marín ◽  
...  
Keyword(s):  
Band Gap ◽  
Transfer Layer ◽  
Hole Transfer ◽  
Ft Ir

El diseño y síntesis de macromoléculas orgánicas conjugadas es de interés en el área de la optoelectrónica, para la fabricación de dispositivos optoelectrónicos, tales como celdas solares orgánicas, celdas solares tipo perovskita, OLEDS, Transistores delgados de efecto de campo orgánicos, sensores, etc. En este trabajo se reporta la simulación molecular mediante DFT de un dendrímero de tipo resorcinareno con segmentos de quinolina y tiofeno en la periferia, designado como D. El dendrímero se sintetizo siguiendo el método convergente de acoplamiento del dendrón quinolínico al centro. El dendrímero D fue caracterizado mediante espectroscopia de 1H-RMN, FT-IR. El estudio de las propiedades ópticas se realizó mediante espectroscopia de UV vis y Fluorescencia estática y dinámica, los resultados indican que el dendrímero presenta una emisión máxima a 574 nm que se ubica en la región verde del espectroelectromagnético. El cálculo del band gap óptico y teórico fue de 2.78 y 3.3 eV respectivamente lo que ubica a este material, dentro de los semiconductores orgánicos. Los valores teóricos de los niveles de energía de los orbitales frontera HOMO y LUMO de 5.52 y 2.18 eV, sugieren su posible aplicación como HTL (hole transfer layer) en la fabricación de una celda solar orgánica de heterounión.

scholarly journals Effects of Au Nanoparticle Addition to Hole Transfer Layer in Organic Photovoltaic Cells Based on Phthalocyanines and Fullerene

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Akihiko Nagata ◽  
Takeo Oku ◽  
Tsuyoshi Akiyama ◽  
Atsushi Suzuki ◽  
Yasuhiro Yamasaki ◽  
...  
Keyword(s):  
Energy Levels ◽  
Photovoltaic Cells ◽  
Organic Photovoltaic ◽  
Au Nanoparticle ◽  
Molecular Orbital Calculations ◽  
Organic Photovoltaic Cells ◽  
Transfer Layer ◽  
Hole Transfer ◽  
Transmission Electron ◽  
Conversion Efficiencies

Phthalocyanines/fullerene organic photovoltaic cells were fabricated and characterized. Effects of Au nanoparticle addition to a hole transfer layer were also investigated, and power conversion efficiencies of the photovoltaic cells were improved after blending the Au nanoparticle into PEDOT:PSS. Nanostructures of the Au nanoparticles were investigated by transmission electron microscopy and X-ray diffraction. Energy levels of molecules were calculated by molecular orbital calculations, and the nanostructures and electronic property were discussed.

Effect of Mn Dopant on Lattice Parameters and Band Gap Energy of Semiconductor ZnO Nanoparticles

2013 ◽  
Vol 829 ◽  
pp. 784-789 ◽  
Author(s):  
Mahmoud Zolfaghari ◽  
Mahshid Chireh
Keyword(s):  
Band Gap ◽  
Zno Nanoparticles ◽  
Room Temperature ◽  
Lattice Parameters ◽  
Memory Storage ◽  
Precipitation Method ◽  
High Electron ◽  
Gap Energy ◽  
Wide Range ◽  
Ft Ir

ZnO belongs to the II-VI semiconductor group with a direct band-gap of 3.2-3.37 eV in 300K and a high exciton binding energy of 60 meV. It has good transparency, high electron mobility, wide, and strong room-temperature luminescence. These properties have many applications in a wide area of emerging applications. Doping ZnO with the transition metals gives it magnetic property at room temperature hence making it multifunctional material, i.e. coexistence of magnetic, semiconducting and optical properties. The samples can be synthesized in the bulk, thin film, and nanoforms which show a wide range of ferromagnetism properties. Ferromagnetic semiconductors are important materials for spintronic and nonvolatile memory storage applications. Doping of transition metal elements into ZnO offers a feasible means of tailoring the band gap to use it as light emitters and UV detector. As there are controversial on the energy gap value due to change of lattice parameters we have synthesized Mn-doped ZnO nanoparticles by co-precipitation method with different concentrations to study the effect of lattice parameters changes on gap energy. The doped samples were studied by XRD, SEM, FT-IR., and UV-Vis. The XRD patterns confirm doping of Mn into ZnO structure. As Mn concentrations increases the peak due to of Mn impurity in FT-IR spectra becomes more pronounces hence confirming concentrations variation. We find from UV-Vis spectra that the gap energy due to doping concentration increases due to the Goldschmidt-Pauling rule this increase depends on dopant concentrations and increases as impurity amount increases.

scholarly journals Synthesis of Fluorene Based Alternating Copolymers using Direct Arylation Polymerization

2021 ◽  
Vol 33 (2) ◽  
pp. 393-398
Author(s):  
Mohd Sani Sarjadi ◽  
Yap Leong Khen ◽  
Xin Lin Wong ◽  
Zuhair Jamain ◽  
Md Lutfor Rahman
Keyword(s):  
Solar Cell ◽  
Band Gap ◽  
Active Layer ◽  
Optical Band Gap ◽  
Direct Arylation ◽  
Low Band Gap ◽  
Alternating Copolymers ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Direct Arylation Polymerization

Many researches have been done to obtain a low band gap and high Polymeric solar cell (PSCs) polymer either by creating new polymer or revising reported polymers from previous studies. In present work, two new copolymers were synthesized through direct arylation polymerization to produce poly(9,9-didodecylfluorene-alt-benzo[c][1,2,5]thiadiazole (P1) and poly(9,9-didodecylfluorene-altthieno[ 3,2-b]thiophene) (P2). The P1 and P2 are donor-accepter copolymers. P1 and P2 were compared to investigate its suitability to be applied in PSCs. The polymers obtained were characterized using FT-IR, NMR and UV-Vis spectroscopy. P1 shows two adsorption bands at λmax1 = 243 nm and λmax2 = 320 nm, whereas P2 also shows two adsorption bands at λmax1 = 243 nm and λmax2 = 427 nm. The optical band gap was calculated, P1 enabled band gap of 3.88 eV while P2 showed band gap of 2.91 eV. This work could be provided an insight to design and synthesize more efficient fluorene-based copolymers as active layer of PSCs in due course.

Hydrazine-assisted preparation of ZnS nanocrystals using N-acetyl-L-cysteine as capping agent

2018 ◽  
Vol 32 (22) ◽  
pp. 1850254
Author(s):  
Reza Sahraei ◽  
Ehsan Soheyli ◽  
Zahra Faraji
Keyword(s):  
Band Gap ◽  
Hydrazine Hydrate ◽  
Absorption Edge ◽  
Emission Intensity ◽  
Band Gap Energy ◽  
Capping Agent ◽  
Time Duration ◽  
Gap Energy ◽  
Ft Ir ◽  
Zns Nanocrystals

Using N-acetyl-L-cysteine (NAC) as capping agent and different amounts of hydrazine hydrate as growth promoter, in this paper, we report a simple way for preparation of aqueous-based ZnS nanocrystals (NCs). The small-sized and well-dispersed NCs with cubic zinc blende structure and size-dependent optical behavior have been characterized by XRD, TEM, FT-IR, UV-Vis, and photoluminescence (PL) measurements. Disappearance of the thiol-related peak in the FT-IR spectrum of NAC-capped ZnS NCs demonstrated the well-passivation of ZnS NCs by deprotonated NAC molecules. Variation of optical properties of ZnS NCs has been studied at different hydrazine amounts and refluxing times. The growth-assisting characteristic of hydrazine hydrate was demonstrated by redshift in absorption edge as the hydrazine amount increased from 5 to 20 mmol, and ensuing decrease in band gap energy of ZnS NCs from 4.47 eV to 4.0 eV. On the other hand, increasing the refluxing time duration up to 20 h, resulted in obvious redshift in absorption edge and subsequent decrease in the band gap energy from 4.56 eV to 3.85 eV. The optical estimation on the size of the as-prepared ZnS NCs was obtained through effective mass approximation. Results indicated that all the NCs are small enough near the excitonic Bohr radius of ZnS which revealed the presence of strong quantum confinement effects. Effect of these parameters on PL emission intensity of ZnS NCs was studied and it was observed that the best emission result is at the presence of 12.5 mmol hydrazine hydrate and during 16 h heating. Finally, analyzing chemical stability of the as-prepared ZnS NCs against H2O2 corrosion demonstrated a well-accepting stability of emission intensity even after 108 min.

scholarly journals Hole Transfer Layer Engineering for CdTe Nanocrystal Photovoltaics with Improved Efficiency

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1348 ◽  
Author(s):  
Yasi Jiang ◽  
Yiyang Pan ◽  
Wanhua Wu ◽  
Kaiying Luo ◽  
Zhitao Rong ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Annealing Temperature ◽  
Transfer Layer ◽  
Inverted Structure ◽  
Solution Processed ◽  
Hole Transfer ◽  
Carrier Recombination ◽  
Cdte Nanocrystal ◽  
Contact Electrode

Interface engineering has led to significant progress in solution-processed CdTe nanocrystal (NC) solar cells in recent years. High performance solar cells can be fabricated by introducing a hole transfer layer (HTL) between CdTe and a back contact electrode to reduce carrier recombination by forming interfacial dipole effect at the interface. Here, we report the usage of a commercial product 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (Spiro) as a hole transfer layer to facilitate the hole collecting for CdTe nanocrystal solar cells. It is found that heat treatment on the hole transfer layer has significant influence on the NC solar cells performance. The Jsc, Voc, and power conversion efficiency (PCE) of NC solar cells are simultaneously increased due to the decreased contact resistance and enhanced built-in electric field. We demonstrate solar cells that achieve a high PCE of 8.34% for solution-processed CdTe NC solar cells with an inverted structure by further optimizing the HTL annealing temperature, which is among the highest value in CdTe NC solar cells with the inverted structure.

scholarly journals A Study on the Development of Organic Thin Film Solar Cell Devicewith Optimized Hole Transfer Layer of PEDOT:PSS

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Paik-Kyun Shin ◽  
Kumar Palanisamy ◽  
Abhirami Kumar ◽  
Katsuhiko Kato ◽  
Shizuyasu Ochiai
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Thin Film Solar Cell ◽  
Organic Thin Film ◽  
Transfer Layer ◽  
Hole Transfer

NiO nanowires as hole-transfer layer for drastic enhancement of CdSe-sensitized photocathodes

2019 ◽  
Vol 43 (10) ◽  
pp. 4075-4081
Author(s):  
Shuang Zhao ◽  
Yuming Dong ◽  
Guangli Wang ◽  
Pingping Jiang ◽  
Yuxia Zhang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Transfer Rate ◽  
Capture Efficiency ◽  
Transfer Layer ◽  
Hole Transfer ◽  
Charge Transfer Rate ◽  
Light Capture

Grass-like NiO nanowires as a hole-transfer layer to improve light capture efficiency and charge transfer rate for a CdSe-sensitized photocathode.

Influence of Li2+ Doping on the Structural and Optical Properties of CaO Synthesized by Sol–Gel Process

2019 ◽  
Vol 07 (01n02) ◽  
pp. 1950002
Author(s):  
Nadir Lalou ◽  
Ahmed Kadari
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Lithium Nitrate ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Sol Gel Process ◽  
Ft Ir ◽  
First Time

This work proposes the synthesis of nanocrystalline calcium oxide (CaO) pure and doped with different concentrations of lithium (Li[Formula: see text]) ions by sol–gel process. Calcium nitrate (Ca(NO[Formula: see text]4H2O; 99.99%) and lithium nitrate (LiNO3; 99.99%) were used as precursors. The synthesized powders were characterized by several techniques such as: UV-Vis transmission spectroscopy, Fourier Transform Infra-red spectroscopy (FT-IR) and X-ray diffraction (XRD). The main objective of this paper is to study the influence of lithium (Li[Formula: see text] ratio) on the structural and optical properties of synthesized powders. The band gap values decreased with the increasing of Li[Formula: see text] ions in CaO lattice; the slight change in the band gap was directly related to the energy transfer between the CaO excited states and the 2s levels of Li[Formula: see text] ions. The influence of Li[Formula: see text] doping on the physical properties of CaO nanocrystalline will be studied for the first time in this work; no literature has previously published this kind of impurities.

Enhanced organic photovoltaic cells with MoOx nanorods as a hole transfer layer

2017 ◽  
Vol 654 (1) ◽  
pp. 17-21
Author(s):  
Jeong-Hwan Ahn ◽  
Joon-Sub Ahn ◽  
Myeong-Jun Jang ◽  
Eun-Mi Han
Keyword(s):  
Photovoltaic Cells ◽  
Organic Photovoltaic ◽  
Organic Photovoltaic Cells ◽  
Transfer Layer ◽  
Hole Transfer

Interface engineering via an insulating polymer for highly efficient and environmentally stable perovskite solar cells

2016 ◽  
Vol 52 (76) ◽  
pp. 11355-11358 ◽  
Author(s):  
Xiaoru Wen ◽  
Jiamin Wu ◽  
Meidan Ye ◽  
Di Gao ◽  
Changjian Lin
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Charge Recombination ◽  
Interface Engineering ◽  
Transfer Layer ◽  
Hole Transfer ◽  
Highly Efficient ◽  
First Time

A tunnelling contact of polystyrene nanofilm was firstly introduced for the first time at the interface of perovskite/hole transfer layer, leading to a significantly reduced charge recombination.

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