Facile synthesis of CuInGaS₂ quantum dot nanoparticles for bilayer-sensitized solar cells (original) (raw)
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Enhanced performance of solar cells via anchoring CuGaS2 quantum dots
Science China Materials, 2017
Ternary I-III-VI quantum dots (QDs) of chalcopyrite semiconductors exhibit excellent optical properties in solar cells. In this study, ternary chalcopyrite CuGaS 2 nanocrystals (2-5 nm) were one-pot anchored on TiO 2 nanoparticles (TiO 2 @CGS) without any long ligand. The solar cell with TiO 2 @CuGaS 2 /N719 has a power conversion efficiency of 7.4%, which is 23% higher than that of monosensitized dye solar cell. Anchoring CuGaS 2 QDs on semiconductor nanoparticles to form QDs/dye co-sensitized solar cells is a promising and feasible approach to enhance light absorption, charge carrier generation as well as to facilitate electron injection comparing to conventional mono-dye sensitized solar cells.
Solid-state colloidal CuInS2quantum dot solar cells enabled by bulk heterojunctions
Nanoscale, 2016
Colloidal copper indium sulfide (CIS) nanocrystals (NCs) are Pb-and Cd-free alternatives for use as absorbers in quantum dot solar cells. In a heterojunction with TiO2, non-annealed ligand-exchanged CIS NCs form solar cells yielding a meager power conversion efficiency (PCE) of 0.15%, with photocurrents plummeting far below predicted values from absorption. Decreasing the amount of zinc during post-treatment leads to improved mobility but marginally improves device performance (PCE = 0.30%). By incorporating CIS into a porous TiO2 network, we saw an overall drastic improvement in device performance, reaching PCEs of 1.16%, mainly from an increase in short circuit current density (Jsc) and fill factor (FF) and a 10-fold increase in internal quantum efficiency (IQE). We have determined that by moving from a bilayer to a bulk heterojunction architecture, we have reduced the trap-assisted recombination as seen in changes in the ideality factor, the intensity dependence of the photocurrent and transient photocurrent (TPC) and photovoltage (TPV) characteristics.
Energy Environ. Sci., 2012
A high-performance quantum dot-sensitized solar cell (QDSSC) is reported, which consists of a TiO 2 /CuInS 2-QDs/CdS/ZnS photoanode, a polysulfide electrolyte, and a CuS counter electrode. The sensitization process involves attaching presynthesized CuInS 2 QDs (3.5 nm) to a TiO 2 substrate with a bifunctional linker, followed by coating CdS with successive ionic layer adsorption and reaction (SILAR) and ZnS as the last SILAR layer for passivation. This process constructs a sensitizing layer that comprises of CdS nanocrystals, closely packed around the earlier-linked CuInS 2 QDs, which serves as the pillars of the layer. The CuS counter electrode, prepared via successive ionic solution coating and reaction, has a small charge transfer resistance in the polysulfide electrolyte. The QDSSC exhibits a short-circuit photocurrent (J sc) of 16.9 mA cm-2 , an open-circuit photovoltage (V oc) of 0.56 V, a fill factor of 0.45, and a conversion efficiency of 4.2% under one-sun illumination. The heterojunction between the CuInS 2 QDs and CdS extends both the optical absorption and incident photon conversion efficiency (IPCE) spectra of the cell to a longer wavelength of approximately 800 nm, and provides an IPCE of nearly 80% at 510 nm. The high TiO 2 surface coverage of the sensitizers suppresses recombination of the photogenerated electrons. This results in a longer lifetime for the electrons, and therefore, the high V oc value. The notably high J sc and V oc values demonstrate that this sensitization strategy, which exploits the quantum confinement reduction and other synergistic effects of the CuInS 2-QDs/CdS/ZnS heterostructure, can potentially outperform those of other QDSSCs.
2017
Quantum dot-sensitized solar cells (QDSSCs) offer new opportunities to address the clean energy challenge, being one of the top candidates for third generation photovoltaics. Like dye-sensitized solar cells (DSSCs), QDSSCs normally use liquid electrolytes that suffer from issues such as evaporation or leakage. In this study a gel polysulfide electrolyte was prepared containing a natural polymer, agar, and was used as a quasi-solid-state electrolyte in solar cells to replace the conventional liquid electrolytes. This gel electrolyte shows almost the same conductivity as the liquid one. The solar cells were fabricated using CuInS2 quantum dots (QDs), previously synthesized, deposited on TiO2 photoanodes by electrophoretic deposition (EPD). CdS was deposited on TiO2 by successive ionic layer adsorption and reaction (SILAR). Reduced graphene oxide (RGO)–Cu2S, brass, and thin film CuxS were used as counter electrodes. Compared to a liquid polysulfide water based electrolyte, solar cells ...
TiO2/Bi2S3/Cu as a working electrode in Quantum Dots Sensitized Solar Cells
2016
Bi2S3 is a promising material for Quantum Dot sensitized solar cells (QDSSCs). Probably the major reasons are: its low toxicity, low cost and its high absorption coefficient. The band gap of bulk Bi2S3 material is 1.3eV but in Quantum Dots(QDs) it varies from 1.3 to 1.7eV. In present work, we are reporting Bi2S3 QDs Sensitized over mesoporous oxide (TiO2) and application of copper Nanoparticles (NPs) fabrication on TiO2/Bi2S3 devices. The deposition of Bi2S3 QDs on TiO2 was done by Successive Ionic Layer Adsorption and Reaction (SILAR) and fabrication of Cu NPs on TiO2/Bi2S3 by electrophoretic deposition method. Finally, the maximum power conversion efficiency (PCE) is 3.90 % for TiO2/Bi2S3/Cu with functionalized multi walled carbon nanotubes (MWCNTs) as a counter electrode.
Electrochimica Acta, 2013
A practical tandem structure with a semitransparent mesh-structured Cu 2 S counter electrode sandwiched between two TiO 2 photoelectrodes has been designed for quantum dot-sensitized solar cells (QDSCs). The mesh-structured Cu 2 S counter electrode exhibits high catalytic activity for polysulfide electrolyte. CdS/CdSe quantum dot-sensitized TiO 2 films have been applied as both top and bottom photoelectrodes to testify the effectiveness of the tandem structure. The influence of the TiO 2 film thickness on the performance of the tandem cell has been systematically studied. The optimized tandem QDSC shows an improved photocurrent and 12-percent increase of efficiency over the top cell with a 4.7 m thick top cell and an 11.0 m thick bottom cell, presenting a new effective approach towards highly efficient QDSCs.
Highly Electrocatalytic Cu2ZnSn(S1–xSex)4 Counter Electrodes for Quantum-Dot-Sensitized Solar Cells
ACS Applied Materials & Interfaces, 2013
Traditional Pt counter electrode in quantum-dotsensitized solar cells suffers from a low electrocatalytic activity and instability due to irreversible surface adsorption of sulfur species incurred while regenerating polysulfide (S n 2− /S 2−) electrolytes. To overcome such constraints, chemically synthesized Cu 2 ZnSn(S 1−x Se x) 4 nanocrystals were evaluated as an alternative to Pt. The resulting chalcogenides exhibited remarkable electrocatalytic activities for reduction of polysulfide (S n 2-) to sulfide (S 2−), which were dictated by the ratios of S/Se. In this study, a quantum dot sensitized solar cell constructed with Cu 2 ZnSn(S 0.5 Se 0.5) 4 as a counter electrode showed the highest energy conversion efficiency of 3.01%, which was even higher than that using Pt (1.24%). The compositional variations in between Cu 2 ZnSnS 4 (x = 0) and Cu 2 ZnSnSe 4 (x = 1) revealed that the solar cell performances were closely related to a difference in electrocatalytic activities for polysulfide reduction governed by the S/Se ratios.
Nano Energy, 2014
The availability of a well-established procedure for fabricating reliable and reproducible counter electrodes for quantum dot sensitized solar cells is currently an issue, limiting both the functional performances of these devices and the possibility to compare results obtained in different laboratories. We present here a simple, cheap and fast method for Cu 2 S counter electrodes fabrication based on spray pyrolysis deposition. Application of prepared counter electrodes to SILAR-sensitized quantum dot solar cells results in high performance devices (photoconversion efficiencies as high as 3.75% and impressive incident photon-to-currentefficient higher than 90%) as well in excellent reproducibility.
Sains Malaysiana, 2020
In this study, rGO/CuInS2 has been successfully prepared onto TiO2 thin film using solvothermal method followed by Ag2S deposition layer by successive ionic layer adsorption and reaction deposition (SILAR) technique. The morphology, structural, and optical properties of TiO2/rGO/CuInS2 thin film were investigated by using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscope (AFM), X-ray diffraction (XRD) and ultra-violet-visible near infrared spectrophotometer (UV-Vis). For electrical properties, electrochemical impedance spectra (EIS) and current-voltage (I-V) test investigated the interfacial charge-transfer resistances and the conversion efficiency of the samples. Results showed that the average particles size of the samples ranged from ±46.52 to ±53.97 nm in diameter. UV-VIS analysis indicated that TiO2/rGO/CuInS2 thin film showed better light absorption capability with the presence of Ag2S deposition layers. Th...