scholarly journals Vacuum-Free and Highly Dense Nanoparticle Based Low-Band-Gap CuInSe2 Thin-Films Manufactured by Face-to-Face Annealing with Application of Uniaxial Mechanical Pressure

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 484
Author(s):  
Matthias Schuster ◽  
Dominik Stapf ◽  
Tobias Osterrieder ◽  
Vincent Barthel ◽  
Peter J. Wellmann
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Coarse Grained ◽  
High Porosity ◽  
Low Band Gap ◽  
Seeding Layer ◽  
X Ray ◽  
Face To Face ◽  
Copper Indium ◽  
Vis Spectroscopy

Copper indium gallium sulfo-selenide (CIGS) based solar cells show the highest conversion efficiencies among all thin-film photovoltaic competition. However, the absorber material manufacturing is in most cases dependent on vacuum-technology like sputtering and evaporation, and the use of toxic and environmentally harmful substances like H2Se. In this work, the goal to fabricate dense, coarse grained CuInSe2 (CISe) thin-films with vacuum-free processing based on nanoparticle (NP) precursors was achieved. Bimetallic copper-indium, elemental selenium and binary selenide (Cu2−xSe and In2Se3) NPs were synthesized by wet-chemical methods and dispersed in nontoxic solvents. Layer-stacks from these inks were printed on molybdenum coated float-glass-substrates via doctor-blading. During the temperature treatment, a face-to-face technique and mechanically applied pressure were used to transform the precursor-stacks into dense CuInSe2 films. By combining liquid phase sintering and pressure sintering, and using a seeding layer later on, issues like high porosity, oxidation, or selenium- and indium-depletion were overcome. There was no need for external Se atmosphere or H2Se gas, as all of the Se was directly in the precursor and could not leave the face-to-face sandwich. All thin-films were characterized with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and UV/vis spectroscopy. Dense CISe layers with a thickness of about 2–3 µm and low band gap energies of 0.93–0.97 eV were formed in this work, which show potential to be used as a solar cell absorber.

scholarly journals Growth of Copper Indium Telluride (Cuinte2) Thin Films Using Electrochemical Route for Photovoltaic Application

2012 ◽  
Vol 12 ◽  
pp. 318-323 ◽  
Author(s):  
Subash Adhikari ◽  
NB Chaure
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Elemental Composition ◽  
Indium Tin Oxide ◽  
Secondary Phase ◽  
Annealed Sample ◽  
X Ray ◽  
Copper Indium ◽  
Electrochemically Deposited ◽  
Indium Telluride

Copper indium di-telluride (CuInTe2; CIT) was electrochemically deposited onto indium tin oxide (ITO) substrate using aqueous medium at various electrodeposition conditions like temperature, pH, stirring rate and concentration of the samples. The resulting thin films were characterized using UV-Visible-NIR spectrophotometer, X-ray diffractometer, scanning electron microscopy and energy dispersive X-ray to find out energy band gap, structural properties, surface morphology and the elemental composition in the film respectively. The resulting films showed a polycrystalline nature with band gap varying from 1.27 to 1.89 eV. The elemental composition of the as deposited and annealed sample showed that the films were mostly copper and tellurium rich. The crystallinity of the films improved after annealing for 5 minutes at 350°C but the secondary phase like CuxTe and InxTe could not be recombined completely.DOI: http://dx.doi.org/10.3126/njst.v12i0.6519 Nepal Journal of Science and Technology 12 (2011) 318-323 

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

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.

Structural, Optical, and Electrical Properties of ZnO/Nb/ZnO Multilayer Thin Films

2014 ◽  
Vol 975 ◽  
pp. 238-242 ◽  
Author(s):  
Adolfo Henrique Nunes Melo ◽  
Petrucio Barrozo Silva ◽  
Marcelo Andrade Macedo
Keyword(s):  
Thin Films ◽  
Peak Position ◽  
Multilayer Thin Films ◽  
Optical And Electrical Properties ◽  
Zno Thin Film ◽  
Energy Band Gap ◽  
X Ray ◽  
Unit Cell Size ◽  
Vis Spectroscopy ◽  
Sputtering System

ZnO multilayers and pure ZnO thin films were deposited onto glass using a sputtering system, and were subsequently characterized by X-ray diffractometry and UV-Vis spectroscopy. The resistivity of the samples was measured by the four-probe method. All films exhibited preferential orientation along the c-axis and the peak position (002) shifted to a lower position, indicating a reduction in the unit cell size. The pure ZnO thin film exhibited a maximum transmittance of approximately 98%, which decreased as the Nb layer increased, thus increasing the absorbance of the multilayer thin films. The energy band gap decreased as the thickness of the metal increased which higher value was 3.18 eV. The resistivity had a minimum of 0.1 × 10-4 Ω m.

Refractive Index Tailoring of Poly(methylmethacrylate) Thin Films by Embedding Silver Nanoparticles

2012 ◽  
Vol 585 ◽  
pp. 134-138 ◽  
Author(s):  
Alisha Goyal ◽  
Jyoti Rozra ◽  
Isha Saini ◽  
Pawan K. Sharma ◽  
Annu Sharma
Keyword(s):  
Thin Films ◽  
Silver Nanoparticles ◽  
Refractive Index ◽  
Band Gap ◽  
Ag Nanoparticles ◽  
Nanocomposite Films ◽  
Ex Situ ◽  
Plasmon Resonance Peak ◽  
Pmma Matrix ◽  
Vis Spectroscopy

Nanocomposite films of Poly (methylmethacrylate) with different concentration of silver nanoparticles were prepared by ex-situ method. Firstly, silver nanoparticles were obtained by reducing the aqueous solution of silver nitrate with sodium borohydride then Ag-PMMA films were prepared by mixing colloidal solution of silver nanoparticles with solution of polymer. Thin solid films were structurally characterized using UV-VIS spectroscopy and TEM. The appearance of surface plasmon resonance peak, characteristic of silver nanoparticles at 420 nm in UV-VIS absorption spectra of Ag-PMMA films confirms the formation of Ag-PMMA nanocomposite. TEM showed Ag nanoparticles of average size 8 nm embedded in PMMA matrix. Analysis of absorption and reflection data indicates towards the reduction in optical band gap and increase in refractive index of the resulting nanocomposite. The synthesized Ag-PMMA nanocomposite has been found to be more conducting than PMMA as ascertained using I-V studies. The decrease in band gap and increase in conductivity can be correlated due to the formation of localized electronic states in PMMA matrix due to insertion of Ag nanoparticles. The PMMA thin films with dispersed silver nanoparticles may be useful for nanophotonic devices.

New tailored organic semiconductors thin films for optoelectronic applications

2021 ◽  
Author(s):  
Dinesh Pathak ◽  
Sanjay Kumar ◽  
Sonali Andotra ◽  
Jibin Thomas ◽  
Navneet Kaur ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cell ◽  
Optical Absorption ◽  
Band Gap ◽  
Organic Semiconductors ◽  
Low Cost ◽  
Organic Thin Film ◽  
Vis Spectroscopy ◽  
Carbon Based

In this study, we have investigated new tailored organic semiconductors materials for the optoelectronic application, such as organic solar cells. The carbon-based organic semiconductor material has promising advantages in organic thin-film form. Moreover, due to its low cost, organic thin-films are suitable and cheaper than inorganic thin-film. The band gap of organic semiconductors materials can be tuned and mostly lies between 2.0eV to 4eV and the optical absorption edge of organic semiconductors typically lies in between 1.7eV to 3eV. They can be easily tailored by modifying the carbon chain and legends and looks promising for engineering the band gap to harness solar spectrum. In this work, with new tailored organic semiconductors the solution route is explored which is low cost processing method. (Anthracen-9-yl) methylene naphthalene-1-amine, 4-(anthracen-9-ylmethyleneamino)-1,5dimethyl-2-phenyl-1H-pyrazol-3-one and N-(anthracen-9-ylmethyl)-3,4-dimethoxyaniline thin-films are processed by spin coating method with changing concentration such as 0.05 wt% and 0.08 wt%. Thin films of Organic semiconductors were prepared on glass substrate and annealed at 55°C. The structural and optical behaviour of (Anthracen-9-yl) methylene naphthalene-1-amine, 4-(anthracen-9-ylmethyleneamino)-1,5dimethyl-2-phenyl-1H-pyrazol-3-one and N-(anthracen-9-ylmethyl)-3,4-dimethoxyaniline organic semiconductors thin films is studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and UV-Visible Spectroscopy technique. The XRD data of synthesized sample suggests the Nano crystallinity of the Organic layers. The SEM micrographs shows the dense packing when we increase the wt% 0.05 to 0.08. Analysis of the optical absorption measurements found that the engineered band gap of synthesized thin films are 2.18eV, 2.35eV, 2.36eV, 2.52eV and 2.65eV which suggest suitability for applications of Optoelectronic devices such as solar cell. Such light weight, eco-friendly and disposable new carbon based materials seems to have potential to replace other traditional hazardous heavy materials for future eco-friendly flat fast electronics. Keywords: Thin-film, solar cell, tailored organic semiconductors, XRD, SEM, UV-Vis spectroscopy.

Effect of vacuum annealing on the properties of one step thermally evaporated Sb2S3 thin films for photovoltaic applications

2021 ◽  
Author(s):  
Emna Gnenna ◽  
Naoufel Khemiri ◽  
Minghua Kong ◽  
Maria Isabel Alonso ◽  
Mounir Kanzari
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
Chemical Compositions ◽  
Optical Parameters ◽  
X Ray ◽  
Vis Spectroscopy ◽  
One Step

Sb2S3 powder was successfully synthesized by solid state reaction technique using high-purity elemental antimony and sulfur. Sb2S3 thin films were deposited on unheated glass substrates by one step thermal evaporation and annealed under vacuum atmosphere for 2 hours at different temperatures 150, 200 and 250 °C. Different characterization techniques were used to better understand the behavior of the Sb2S3 material. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of pure Sb2S3 powder with lattice parameters a = 11.07 Å, b = 11.08 Å and c = 3.81 Å. The effect of vacuum annealing temperature on the properties of the films was studied. XRD analysis revealed that as-deposited and annealed films at 150ºC were amorphous in nature whereas those annealed at T ≥ 200°C were polycrystalline with a preferred orientation along (201) plane. The crystallite size of the polycrystalline films showed a decrease from 75.8 to 62.9 nm with the increase of the annealing temperature from 200 to 250 °C. The Raman analysis showed several peaks corresponding to the stibnite Sb2S3 phase. The surface morphology of the films was examined by atomic force microscopy (AFM). The surface roughness decreases slightly as the transformation from the amorphous to the crystalline phase occurs. The chemical compositions of Sb2S3 films were analyzed by energy dispersive X-ray spectroscopy (EDS), revealing that all films were Sb-rich. The optical parameters were estimated from the transmittance and reflectance spectra recorded by UV-Vis spectroscopy. A reduction in the direct band gap energy from 2.12 to 1.70 eV with the increase of annealing temperature was also found.

Growth and Characterizations of Indium-Doped Pentacene Thinfilm Prepared by Thermal Co-Evaporation as a Novel Nanomaterial

2015 ◽  
Vol 1131 ◽  
pp. 35-38
Author(s):  
Navaphun Kayunkid ◽  
Annop Chanhom ◽  
Chaloempol Saributr ◽  
Adirek Rangkasikorn ◽  
Jiti Nukeaw
Keyword(s):  
Thin Films ◽  
Carrier Concentration ◽  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Charge Carrier Mobility ◽  
Electrical Measurements ◽  
X Ray ◽  
Force Microscopy ◽  
Vis Spectroscopy ◽  
Hybrid Thin Films

This research is related to growth and characterizations of indium-doped pentacene thin films as a novel hybrid material. Doped films were prepared by thermal co-evaporation under high vacuum. The doping concentration was varied from 0% to 50% by controlling the different deposition rate between these two materials while the total thickness was fixed at 100 nm. The hybrid thin films were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-Visible spectroscopy to reveal the physical and optical properties. Moreover, the electrical properties of ITO/indium-doped-pentacene/Al devices i.e. charge mobility and carrier concentration were determined by considering the relationship between current-voltage and capacitance-voltage. AFM results identify that doping of indium into pentacene has an effect on surface properties of doped films i.e. the increase of surface grain size. XRD results indicate that doping of metal into pentacene has an effect on preferential orientation of pentacene’s crystalline domains. UV-Vis spectroscopy results show evolution of absorbance at photon energy higher than 2.7 eV corresponding to absorption from oxide of indium formed in the films. Electrical measurements exhibit higher conductivity in doped films resulting from increment of both charge carrier mobility and carrier concentration. Furthermore, chemical interactions taken place inside the doped films were investigated by x-ray photoelectron spectroscopy (XPS) in order to complete the remaining questions i.e. how do indium atoms interact with the neighbor molecules?, what is the origin of the absorption at E > 2.7 eV? Further results and discussions will be presented in the publication.

Study on integration of aluminum-doped zinc oxide (AZO) thin films with graphene oxide (GO)

2018 ◽  
Vol 32 (19) ◽  
pp. 1840044
Author(s):  
Aditya Dalal ◽  
Animesh Mandal ◽  
Shubhada Adhi ◽  
Kiran Adhi
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Aluminum Doped Zinc Oxide ◽  
Uv Visible

Aluminum (0.5 at.%)-doped ZnO (AZO) thin films were deposited by pulsed laser deposition technique (PLD) in oxygen ambient of 10[Formula: see text] Torr. The deposited thin films were characterized by x-ray diffraction (XRD), photoluminescence (PL), Raman spectroscopy and uv–visible spectroscopy (UV–vis). Next, graphene oxide (GO) was synthesized by Hummers method and was characterized by XRD, UV–vis spectroscopy, Raman spectroscopy and transmission electron microscopy (TEM). Thereafter, GO solution was drop-casted on AZO thin films. These films were then characterized by Raman Spectroscopy, UV–vis spectroscopy and PL. Attempt is being made to comprehend the modifications in properties brought about by integration.

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