This paper reported some results about intrinsic nanocrystalline silicon thin films deposited by high frequency (HF) sputtering on p-type c-Si substrates at low temperature. Samples were examined by atomic force micro...This paper reported some results about intrinsic nanocrystalline silicon thin films deposited by high frequency (HF) sputtering on p-type c-Si substrates at low temperature. Samples were examined by atomic force microscopy (AFM), X-ray diffraction (XRD), infrared absorption, and ellipsometry. XRD measurements show that this film has a new microstructure, which is different from the films deposited by other methods. The ellipsometry result gives that the optical band gap of the film is about 2.63 eV. In addition, the n-type nc-Si∶H/p-type c-Si heterojunction solar cell, which has open circuit voltage (U oc ) of 558 mV and short circuit current intensity (I sc ) of 29 mA/cm2, was obtained based on the nanocrystalline silicon thin film. Irradiated under AM1.5, 100 mW/cm2 light intensity, the U oc , I sc , and FF can keep stable for 10 h.展开更多
Hydrogenated amorphous Si （a-Si：H） is a promising material for photovoltaic applications due to its low cost, high abundance, long lifetime, and non-toxicity. We demonstrate a device designed to investigate the eff...Hydrogenated amorphous Si （a-Si：H） is a promising material for photovoltaic applications due to its low cost, high abundance, long lifetime, and non-toxicity. We demonstrate a device designed to investigate the effect of nanostructured back reflectors on quantum efficiency in photovoltaic devices. We adopt a superstrate configuration so that we may use conventional industrial light trapping strategies for thin film solar cells as a reference for comparison. We controlled the nanostructure parameters via a wafer-scale self-assembly technique and systematically studied the relation between nanostructure size and photocurrent generation. The gain/loss transition at short wavelengths showed red-shifts with decreasing nanostructure scale. In the infrared region the nanostructured back reflector shows large photocurrent enhancement with a modified feature scale. This device geometry is a useful archetype for investigating absorption enhancement by nanostructures.展开更多
Mesoscopic lead halide perovskite solar cells typically use TiO2 nanoparticle films as the scaffolds for electron-transport pathway and perovskite deposition. Here, we demonstrate that swelling-induced mesoporous bloc...Mesoscopic lead halide perovskite solar cells typically use TiO2 nanoparticle films as the scaffolds for electron-transport pathway and perovskite deposition. Here, we demonstrate that swelling-induced mesoporous block copolymers can be templates for producing three- dimensional TiO2 networks by combining the atomic layer deposition technique. Thickness adjustable TiO2 network is an excellent alternative scaffold material for efficient per- ovskite solar cells. Our best performing cells using such a 270 nm thick template have achieved a high efficiency of 12.5 % with pristine poly-3-hexylthiophene as a hole transport material. The high performance is attributed to the direct transport pathway and high absorption of scaf- folds, small leakage current and largely reduced recombi- nation rate at interfaces. The results show that TiO2 network architecture is a promising scaffold for meso- scopic perovskite solar cells.展开更多
Highly efficient and stable polymer solar cells （PSCs） have been fabricated by adopting solution-derived hybrid poly（ethylene glycol）-titanium oxide （PEG-TiOx） nanocomposite films as a novel and universal cathod...Highly efficient and stable polymer solar cells （PSCs） have been fabricated by adopting solution-derived hybrid poly（ethylene glycol）-titanium oxide （PEG-TiOx） nanocomposite films as a novel and universal cathode buffer layer （CBL）, which can greatly improve device performance by reducing interface energy barriers and enhancing charge extraction/collection. The performance of inverted PSCs with varied bulk-heterojunctions （BHJs） based on this hybrid nanocomposite CBL was found to be much better than those of control devices with a pure TiOx CBL or without a CBL. An excellent power conversion efficiency up to 9.05% under AM 1.5G irradiation （100 mW-cm^-2） was demonstrated, which represents a record high value for inverted PSCs with TiOx-based interface materials.展开更多
Quaternary chalcogenide Cu2FeSnS4 （CFTS） nanoparticles, as a kind of potential absorber layer material in thin film solar cells （TFSCs）, were successfully synthesized by using a convenient solvothermal method. Alk...Quaternary chalcogenide Cu2FeSnS4 （CFTS） nanoparticles, as a kind of potential absorber layer material in thin film solar cells （TFSCs）, were successfully synthesized by using a convenient solvothermal method. Alkali element K is incorporated into CFTS thin films in order to fiLrther improve the surface morphology and the optical properties of related films. X-ray diffraction （XRD）, Raman spectroscopy and field emission scanning electron microscopy （FESEM） were used to characterize the phase purity, morphology and composition of CFTS particles and thin films. The results show that the particle elemental ratios of Cu/（Fe＋Sn） and Fe/Sn are 1.2 and 0.9, respectively, which are close to the characteristics of stoichiometric CFTS. The band gaps of CFTS films before and after doping K ions are estimated to be 1.44 eV and 1.4 eV with an error of ±0.02 eV.展开更多
We report the fabrication of CuI-Si heterojunction solar cells with carbon nanotubes （CNTs） as a transparent electrode. A flexible CNT network was transferred onto tile top of a polycrystalline CuI layer, making a c...We report the fabrication of CuI-Si heterojunction solar cells with carbon nanotubes （CNTs） as a transparent electrode. A flexible CNT network was transferred onto tile top of a polycrystalline CuI layer, making a conformal coating with good contact with the underlying CuI. The solar cells showed power conversion efficiencies in the range of 6% to 10.5%, while the efficiency degradation was less than 10% after the device was stored in air for 8 days. Compared with conventional rigid electrodes such as indium tin oxide （ITO） glass, the flexibility of the CNT films ensures better contact with the active layers and removes the need for press-contact electrodes. Degraded cells can recover their original performance by acid doping of the CNT electrode. Our results suggest that CNT films are suitable electrical contacts for rough materials and structures with an uneven surface.展开更多
Generally, nanoparticles are easy to aggregate due to their nano sizes, which influence the physical and chemical properties. In this work, a dispersion treatment of the TiO2 nanoparticles with different average sizes...Generally, nanoparticles are easy to aggregate due to their nano sizes, which influence the physical and chemical properties. In this work, a dispersion treatment of the TiO2 nanoparticles with different average sizes was employed to improve the disper- sion of TiO2 nanoparticles, in order to prepare flexible photoanodes for dye-sensitized solar cells （DSCs） with novel photovol- talc properties at a low temperature. The effects of dispersion treatment on the dispersion of TiO2 nanoparticles, including the viscosities of the binder-free TiO2 paste, the morphologies and textural properties of nanoparticle-TiO2 films, and the photo- voltaic properties of the flexible DSCs, were investigated. Flexible indium-tin oxide （ITO）-coated polyethylene naphthalate （PEN） substrates with sputter deposited Pt were employed as the transparent flexible counter electrodes. A short-circuit photo- current density of 9.62 mA·cm^-2, an open-circuit voltage of 0.757 V, a fill factor of 0.589 and an overall light-to-energy con- version efficiency of 4.29% for the flexible DSCs under AM1.5 illumination of 100 mW·cm^-2 were obtained with dispersion treatment. A 30.8% increment of the energy conversion efficiency for DSCs made by dispersion treatment was obtained com- pared with that made without dispersion treatment.展开更多
文摘This paper reported some results about intrinsic nanocrystalline silicon thin films deposited by high frequency (HF) sputtering on p-type c-Si substrates at low temperature. Samples were examined by atomic force microscopy (AFM), X-ray diffraction (XRD), infrared absorption, and ellipsometry. XRD measurements show that this film has a new microstructure, which is different from the films deposited by other methods. The ellipsometry result gives that the optical band gap of the film is about 2.63 eV. In addition, the n-type nc-Si∶H/p-type c-Si heterojunction solar cell, which has open circuit voltage (U oc ) of 558 mV and short circuit current intensity (I sc ) of 29 mA/cm2, was obtained based on the nanocrystalline silicon thin film. Irradiated under AM1.5, 100 mW/cm2 light intensity, the U oc , I sc , and FF can keep stable for 10 h.
文摘Hydrogenated amorphous Si （a-Si：H） is a promising material for photovoltaic applications due to its low cost, high abundance, long lifetime, and non-toxicity. We demonstrate a device designed to investigate the effect of nanostructured back reflectors on quantum efficiency in photovoltaic devices. We adopt a superstrate configuration so that we may use conventional industrial light trapping strategies for thin film solar cells as a reference for comparison. We controlled the nanostructure parameters via a wafer-scale self-assembly technique and systematically studied the relation between nanostructure size and photocurrent generation. The gain/loss transition at short wavelengths showed red-shifts with decreasing nanostructure scale. In the infrared region the nanostructured back reflector shows large photocurrent enhancement with a modified feature scale. This device geometry is a useful archetype for investigating absorption enhancement by nanostructures.
文摘Mesoscopic lead halide perovskite solar cells typically use TiO2 nanoparticle films as the scaffolds for electron-transport pathway and perovskite deposition. Here, we demonstrate that swelling-induced mesoporous block copolymers can be templates for producing three- dimensional TiO2 networks by combining the atomic layer deposition technique. Thickness adjustable TiO2 network is an excellent alternative scaffold material for efficient per- ovskite solar cells. Our best performing cells using such a 270 nm thick template have achieved a high efficiency of 12.5 % with pristine poly-3-hexylthiophene as a hole transport material. The high performance is attributed to the direct transport pathway and high absorption of scaf- folds, small leakage current and largely reduced recombi- nation rate at interfaces. The results show that TiO2 network architecture is a promising scaffold for meso- scopic perovskite solar cells.
文摘Highly efficient and stable polymer solar cells （PSCs） have been fabricated by adopting solution-derived hybrid poly（ethylene glycol）-titanium oxide （PEG-TiOx） nanocomposite films as a novel and universal cathode buffer layer （CBL）, which can greatly improve device performance by reducing interface energy barriers and enhancing charge extraction/collection. The performance of inverted PSCs with varied bulk-heterojunctions （BHJs） based on this hybrid nanocomposite CBL was found to be much better than those of control devices with a pure TiOx CBL or without a CBL. An excellent power conversion efficiency up to 9.05% under AM 1.5G irradiation （100 mW-cm^-2） was demonstrated, which represents a record high value for inverted PSCs with TiOx-based interface materials.
基金supported by National Natural Science Foundation of China(No.51674026)the Fundamental Research Funds for the Central Universities in 2015(No.FRF-BD-15-004A)
文摘Quaternary chalcogenide Cu2FeSnS4 （CFTS） nanoparticles, as a kind of potential absorber layer material in thin film solar cells （TFSCs）, were successfully synthesized by using a convenient solvothermal method. Alkali element K is incorporated into CFTS thin films in order to fiLrther improve the surface morphology and the optical properties of related films. X-ray diffraction （XRD）, Raman spectroscopy and field emission scanning electron microscopy （FESEM） were used to characterize the phase purity, morphology and composition of CFTS particles and thin films. The results show that the particle elemental ratios of Cu/（Fe＋Sn） and Fe/Sn are 1.2 and 0.9, respectively, which are close to the characteristics of stoichiometric CFTS. The band gaps of CFTS films before and after doping K ions are estimated to be 1.44 eV and 1.4 eV with an error of ±0.02 eV.
基金This work is supported by the National Natural Science Foundation of China （NSFC, Grant No.50972067） and the 863 Program （No. 2009AA05Z423）. A. Cao acknowledges the support by the National Science Foundation of China （NSFC, No. 51072005） and C. Huang acknowledges NSFC No. 90922004 for financial support.
文摘We report the fabrication of CuI-Si heterojunction solar cells with carbon nanotubes （CNTs） as a transparent electrode. A flexible CNT network was transferred onto tile top of a polycrystalline CuI layer, making a conformal coating with good contact with the underlying CuI. The solar cells showed power conversion efficiencies in the range of 6% to 10.5%, while the efficiency degradation was less than 10% after the device was stored in air for 8 days. Compared with conventional rigid electrodes such as indium tin oxide （ITO） glass, the flexibility of the CNT films ensures better contact with the active layers and removes the need for press-contact electrodes. Degraded cells can recover their original performance by acid doping of the CNT electrode. Our results suggest that CNT films are suitable electrical contacts for rough materials and structures with an uneven surface.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2011AA-050522)Sanjiang-yuan Scientific Program of Qinghai Science & Technology Department(Grant No. 2010-N-S03)the Ministry of Science & Technology (MOST) International S&T Cooperation Program of China (Grant No. 2010DFA-64360)
文摘Generally, nanoparticles are easy to aggregate due to their nano sizes, which influence the physical and chemical properties. In this work, a dispersion treatment of the TiO2 nanoparticles with different average sizes was employed to improve the disper- sion of TiO2 nanoparticles, in order to prepare flexible photoanodes for dye-sensitized solar cells （DSCs） with novel photovol- talc properties at a low temperature. The effects of dispersion treatment on the dispersion of TiO2 nanoparticles, including the viscosities of the binder-free TiO2 paste, the morphologies and textural properties of nanoparticle-TiO2 films, and the photo- voltaic properties of the flexible DSCs, were investigated. Flexible indium-tin oxide （ITO）-coated polyethylene naphthalate （PEN） substrates with sputter deposited Pt were employed as the transparent flexible counter electrodes. A short-circuit photo- current density of 9.62 mA·cm^-2, an open-circuit voltage of 0.757 V, a fill factor of 0.589 and an overall light-to-energy con- version efficiency of 4.29% for the flexible DSCs under AM1.5 illumination of 100 mW·cm^-2 were obtained with dispersion treatment. A 30.8% increment of the energy conversion efficiency for DSCs made by dispersion treatment was obtained com- pared with that made without dispersion treatment.
