Sonochemical synthesis of CuIn0.7Ga0.3Se2 nanoparticles for thin film photo absorber application (original) (raw)
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Energy & Environmental Science, 2011
We report, for the first time, colloidal synthesis of quinary CuIn 1Àx Ga x (S y Se 1Ày) 2 (CIGSSe) nanocrystals across the entire composition range (x,y) ¼ 0 to 1 with band gaps tunable in the range of 0.98 to 2.40 eV by facile chemical synthesis. As a proof-ofconcept, thin-film solar cells made by using the CIGSSe nanocrystal inks as an absorber layer precursor exhibited an efficiency over 1% under AM 1.5 illumination. Colloidal semiconductor nanocrystals have excellent optoelectronic properties, photo-stability, and long-term dispersion stability, making them well-suited for incorporation into photovoltaic device fabrication processes. 1 The utilization of solution-processable nanocrystals permits the use of relatively low-cost manufacturing equipment so as to greatly reduce the overall fabrication cost of solar cells. 2 One representative example is that absorber layers can be facilely prepared by deposition of a nanocrystal solution, the so-called nanocrystal inks, on a substrate via a variety of solution-based techniques, such as spray deposition, dip-coating, slip casting, inject-printing, screen printing etc., 3 thereby enabling the development of high-throughput roll-to-roll processing. CuIn 1Àx Ga x (S y Se 1Ày) 2 (CIGSSe) has a high optical absorption coefficient, good photodurability, and the desired optical band-gap range, representing as a great light-harvesting material for thin film solar cells. 4 The power-conversion-efficiency of 16.03% CIGSSe-based solar cells was recently achieved on a 30 cm  30 cm sized sub-module, exhibiting an efficiency comparable to crystalline Si-based photovoltaics. 5 Band-gap energies of the CIGSSe system can be tuned from 0.98 to 2.40 eV, wider than its quaternary systems including CISSe (0.98 to 1.46 eV), CIGS (1.46 to 2.4 eV), CIGSe (0.98 to 1.68 eV), and CGSSe (1.68 to 2.4 eV), providing advantageous characteristics for use in double-graded or tandem cell designs. 6 On the other hand, utilizing colloidal CIGSSe nanocrystals for use as an absorber layer precursor could achieve quinary composition uniformity over a large device area that is hardly attainable by vacuum-deposited techniques. 7 However, the synthesis of CIGSSe nanocrystals represents significant difficulty in synthesis due to the complicated phase diagram of quinary alloys. Achieving compositional and structural control of CIGSSe nanocrystals requires precise control of the atomic ratios for both In/Ga and S/Se in the synthesis, which is more challenging than that of quaternary or ternary nanocrystals 8 in which one set of alloying elements (e.g., In and Ga for CuIn x Ga 1Àx S 2 8g) was stoichiometry-adjusted in most cases. To the best of our knowledge, no CIGSSe nanocrystal synthesis across the entire composition range has been reported.
Journal of Alloys and Compounds, 2015
In this paper, we report a novel and simple solution-based approach for the fabrication of chalcopyrite Cu(In,Ga)Se 2 thin film solar cells. An aqueous co-precipitation method based on metal selenites, M 2 (SeO 3 ) x (M ¼ Cu, In, Ga) precursors was investigated. The resulting powder, dispersed in a binder to form an ink, was coated on a substrate by doctor blade technique. A soft annealing treatment allowed the reduction of metal selenites into selenides. Further rapid thermal processing (RTP) achieved crystalline chalcopyrite absorber. The obtained layer provides good compositional control and adequate morphology for solar cell applications. The water-based synthesis is a sustainable and simple procedure, and together with doctor blade printing, provides a potential cost-effective advantage over conventional fabrication processes (vacuum-based deposition techniques). The short circuit current (J SC ), open circuit voltage (V OC ), fill factor (FF), and total area power conversion efficiency (Eff.) of the device are 26 mA/ cm 2 , 450 mV, 62%, and 7.2%, respectively. The effective band gap of 1.12 eV confirmed Ga-incorporation in the CIGS crystal lattice.
Materials Science in Semiconductor Processing, 2020
Water-soluble Cu 2-x Se (x ¼ 0.2) nanoparticles (NPs) were synthesized by an eco-friendly modified chemical coprecipitation method at 70 � C within a short reaction time of 15 min using ascorbic acid. Cu 2-x Se NPs showed pseudo-spherical and hexagonal shapes with sizes in the range of 20-50 nm. XRD analysis showed cubic structure to Cu 2-x Se NPs. Thin films of Cu 2À x Se were deposited by drop-casting the synthesized Cu 2-x Se NPs solution using polyvinylpyrrolidone binder and their physical properties were investigated. The annealed Cu 2-x Se NPs thin film showed a direct optical band gap of 1.82 eV and an indirect band gap of 1.69 eV. Hall Effect measurements of the annealed films showed p-type conductivity with a carrier concentration of 3.18 � 10 19 cm À 3 , resistivity of 1.31 � 10 À 1 Ω-cm, and hole mobility of 1.5 cm 2 /V-s. In order to investigate the potential of Cu 2-x Se NPs as an absorber, solar cells with a device configuration of soda-lime glass (SLG)/Mo/Cu 2-x Se NPs/CdS/i-ZnO/Al:ZnO/Ni/Ag were fabricated and tested, which showed a power conversion efficiency (PCE) of 0.095%. Even though the Cu 2x SeNPs solar cell showed low PCE, the use of environmentally benign reducer like ascorbic acid offers the benefit of eco-friendliness and compatibility of water-soluble Cu 2-x Se NPs synthesis, and its ultimate use in solar cell as well as other applications.
Properties of Sonochemically Prepared CuIn x Ga 1-x S 2 and CuIn x Ga 1-x Se 2
Acta Physica Polonica A, 2014
Nanoparticles of chalcopyrites copper indium gallium sulde (CuInxGa1−xS2 or CIGS) and copper indium gallium selenide (CuInxGa1−xSe2 or CIGSe) were fabricated sonochemically. They were characterized by Xray diraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, high resolution transmission electron microscopy, selected area electron diraction, and diuse reectance spectroscopy. The electrical and photoelectrical properties of the fabricated nanomaterials were investigated.
ACS Applied Materials & Interfaces, 2013
Chalcopyrite-based solar cell deposited by solution processes is of great research interest because of the ease of fabrication and cost effectiveness. Despite the initial promising results, most of the reported methods encounter challenges such as limited grain growth, carbon-rich interlayer, high thermal budget, and the presence of secondary Cu-rich phases, which limit the power conversion efficiency (PCE). In this paper, we develop a new technique to deposit large grain, carbon-free CISSe absorber layers from aqueous nanoparticle/ precursor mixture which resulted in a solar cell with PCE of 6.2%. CuCl 2 , InCl 3 , and thiourea were mixed with CuS and In 2 S 3 nanoparticles in water to form the unique nanoparticle/ precursor solution. The Carbon layer formation was prevented because organic solvents were not used in the precursor. The copper-rich (CuS) nanoparticles were intentionally introduced as nucleation sites which accelerate grain growth. In the presence of nanoparticles, the grain size of CISSe film increased by a factor of 7 and the power conversion efficiency of the solar cell is 85% higher than the device without nanoparticle. This idea of using nanoparticles as a means to promote grain growth can be further exploited for other types of chalcopyrite thin film deposited by solution methods.
Synthesis and Photodetection Properties of Sonochemically Exfoliated Cu0.2Sn0.8Se Nanoparticles
Journal of Nano- and Electronic Physics, 2020
Transition metal chalcogenides (TMCs) with atomically minute structure have shown excessive potential for their optoelectronics field applications and their counterparts. TMCs unique layer dependent properties have pinched increasing consideration of scientists. Here, the high yield synthesis of atomically minute Cu0.2Sn0.8Se nanoparticles has been reported. The nanoparticles are synthesised by sonochemical exfoliation technique. The exfoliated Cu0.2Sn0.8Se nanoparticles have orthorhombic lattice structure which is confirmed from powder X-ray Diffraction with Pnma space group. The lateral morphology of the assynthesized nanoparticles examined under transmission electron microscopy showed them to be of uniform spherical shape. The selected area electron diffraction showed a spot pattern stating the particles to be single crystalline. Moreover, the photodetector based on Cu0.2Sn0.8Se nanoparticles thin film is fabricated. The periodic 670 nm laser illumination of power intensity 3 mW/cm 2 is used to study the detector properties. The enhanced photo responsivity and specific detectivity is observed along with fast response. The outstanding detection properties are revealed from the responsivity, specific detectivity, and external quantum efficiency (EQE) of Cu0.2Sn0.8Se nanoparticles-based photodetector.
Formation of CuIn(SxSe1−x)2 microcrystals from CuInSe2 nanoparticles by two step solvothermal method
Journal of Alloys and Compounds, 2015
Here we introduced a two-step reaction to synthesize highly crystalline CuIn(S 1Àx Se x) 2 (CuInSSe) microcrystals from CuInSe 2 nanocrystals. CuInSSe micro particles can be obtained without toxic selenization or sulfurization process and the composition of sulfur and selenium can be easily controlled by varying the amount of precursor at different stages of the reactions. This synthetic route allows a technique that is simple and non-toxic together with the possibility of tuning the composition. XRD, HRTEM and SAED analysis of the final product confirmed the pure phase formation of CuInSSe. EDAX analysis shows the compositions of the final product matched with CuInSSe and the compositions of the product can tune by the reaction parameter. UV-Vis absorption spectra reveals a clear blue shift due to an increase in band gap with the increase of sulfur content. Initial photocurrent response suggests its possibility to be used as absorber materials in thin film solar cells.
Solution-processed CuIn(S,Se)2 absorber layers for application in thin film solar cells
Thin Solid Films, 2014
A pure solution-based approach is proposed for the fabrication of high quality CuIn(S,Se) 2 (CIS) thin films. This is an alternative procedure to the hydrazine-based route and involves the dissolution of metal chalcogenides in a safer solvent combination. The solvent mixture used in this work has the same advantages as hydrazine, such as good solubility of metal chalcogenides and clean decomposition, which is a prerequisite for high quality absorber layers. The solvents that are used are also much less toxic compared to hydrazine and can potentially result in a more feasibly industrially scalable deposition technology for CIS and the related alloys including Cu(In,Ga)(S,Se) 2 (CIGS). The characterization of the obtained thin film material verifies the presence of the CIS chalcopyrite phase with good crystal growth.
Thin Solid Films, 2003
A novel non-vacuum process in which water based inks formulated using nanoparticles of mixed oxides of Cu, In and Ga are used to deposit a precursor layer of fixed Cuy(InqGa) ratio on a rigid or a flexible substrate of choice using printing techniques. The precursor layer is converted to a CuIn Ga Se (CIGS) absorber layer of uniform composition via two sequential gas solid 1yx x 2 reactions of reduction and selenization. Solar cells fabricated in CIGS films prepared by this technique have conversion efficiency approaching 13.6% on glass substrate and over 10% on Mo foil. Compositional uniformity, high materials' utilization and the use of low-cost equipment make this process suitable for large-scale production of low-cost CIGS modules.
Journal of Nanoparticle Research, 2012
The research for tunable synthesis and characterization techniques is important for the investigation of nanomaterials. Herein we developed old precipitation reaction for the morphology-and phasetunable synthesis of copper selenides nanostructures at room temperature, avoiding tedious preparation of selenium precursors, such as selenite or selenosulfate. The molar ratio of Cu 2? and Se sources served the function of a switch for selectively synthesis of stoichiometric CuSe and non-stoichiometric Cu 2-x Se. Nanorod and lath-like CuSe formed with excess of selenium source, while tremella-shaped Cu 2-x Se responded to the 1:1 of Cu 2? /Se or excess of copper source. The structures of nanocrystals, especially the lifelike surface, were characterized in detail by electron microscopy techniques, such as STEM. Novel nanostructures put up the excellent absorption properties in the visible light region, respectively, and could bear potential applications in solar cell devices in the future. This strategy offered a convenient, mild and energy-efficient route for the preparation of other mental chalcogenides nanocrystals with different morphologies or tunable phases.