提交时间: 2017-05-02
摘要: Polycrystalline ZnSnN2 thin films were successfully prepared by DC magnetron sputtering at room temperature. Both the as-deposited and annealed films showed n-type conduction, with electron concentration varying between 1.6 x 10[18] and 2.3 x 10[17] cm[-3
提交时间: 2017-05-02
摘要: Cathode interlayer is essential to inverted bulk heterojunction polymer solar cells [PSCs]. A series of zwitterionic ammonium and neutral amino organic molecules are introduced into inverted PSCs as cathode interlayer and power conversion efficiency [PCE]
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: We used cesium stearate (CsSt) to modify the interface of the electron- extracting contact in inverted organic solar cells. Surface microstructure, optical properties, and electrical characterization as well as exciton generation rate and dissociation probability were investigated to understand the impact of CsSt on the interface contact. The results indicated that by incorporation of CsSt, the surface morphology and energy level as well as conductivity of a zinc oxide (ZnO) film were improved. On the basis of the above properties, highly efficient inverted organic solar cells have been demonstrated by using a ZnO nanoparticle film and CsSt stacked bilayer structure as the cathode interfacial layer. The insertion of a CsSt layer between the ZnO film and active layer improved the electron extraction efficiency, and a high power conversion efficiency (PCE) of 8.69% was achieved. The PCE was improved by 20% as compared to the reference device using a ZnO-only electron extraction layer.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Environmentally benign hybrid interlayers are prepared by modifying the zinc sulfide (ZnS) with phenanthroline/derivatives and utilized in inverted polymer solar cells (PSCs). Performances of the inverted PSCs are improved enormously by incorporating these hybrid inter- layers, as which can effectively improve the energy level alignment, electron mobility, surface morphology, and interfacial contact. Greatly improved power conversion efficiencies (PCEs) of 7.79%, 8.00%, 7.47%, and 7.56% are achieved with these hybrid interlayers ZnS-BCP, ZnS-Bphen, ZnS-Mphen, and ZnS-Phen, respectively, compared to the PCE of 2.99% of the reference ZnS-based device, based on PTB7:PC71BM active layer. Our results demonstrate that hybrid interfacial materials comprising inorganic and organic semiconductor possess promising potential to improve the performance of organic electronic devices, and set an example to develop this novel class of interfacial materials for electronic devices.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Planar heterojunction perovskite solar cells were fabricated through a low temperature approach. We find that the device performance significantly depends on the external bias before and during measurements. By appropriate optimization of the bias conditions, we could achieve an 8-fold increase in the power conversion efficiency. The significant improvement in device performance might be caused by the ion motion in the perovskite under the external electric field.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: We reported the favorable cathode buffer layer based on a blend of ZnO nanoparticles (NPs) and TiO2 nanorods (NRs) applied to inverted solar cells. In addition to the high optical transmittance, the resultant blend film gave a relatively dense film with lower roughness than that of the respective single-component film. This improved the interface contact between the buffer layer and photoactive layer and therefore reduced the contact resistance and leakage current. Moreover, the combination of NRs and NPs increased the efficiency of electron transport and collection by providing both a direct path for electron transport from TiO2 NRs and a large contact area between ZnO NPs and the active layer. Consequently, both the short-circuit current density (Jsc) and fill factor (FF) in the device were improved, leading to an improvement of the device performance. The best power conversion efficiency (PCE) based on the blend film as the buffer layer reached 8.82%, which was preferable to those of a single ZnO NP film (7.76%) and a TiO2 NR-based device (7.66%). KEYWORDS: ZnO nanoparticles, TiO2 nanorods, blend film, cathode buffer layer, inverted solar cells
提交时间: 2017-05-02
摘要: Crystalline silicon thin film [c-Si TF] solar cells with an active layer thickness of a few micrometers may provide a viable pathway for further sustainable development of photovoltaic technology, because of its potentials in cost reduction and high effic
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: In this paper, flexible Ag electrodes with a hexagonal micromesh structure were fabricated on PET substrate using a photolithography technique. The effect of film thickness on optical and electrical properties of Ag electrodes was investigated systematically. Furthermore, these flexible transparent Ag mesh electrodes were firstly applied to a polymer dispersed liquid crystal (PDLC) device and its performance was evaluated. All of the Ag electrodes exhibited a high average transmittance of about 80.2–85.0% in the visible range (400–800 nm), and the minimum sheet resistance value reached 8.2 U sq 1. The prepared Ag mesh also showed an excellent performance of adhesion and bending, demonstrating its superior durability. The PDLC device based on Ag mesh electrodes showed comparable performance with that using ITO electrodes, indicating that the Ag mesh film can be a good substitution for ITO electrodes in PDLC devices and may find practical application in large area flexible devices.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Three 3,4-dithienyl-substituted polythiophene derivatives have been synthesized and characterized. Polymer P2 exhibits the widest light absorption spectrum of the polymers in its polymer chain, which has an alternative donor-acceptor structure. Copolymers blended with 6,6-phenyl-C71-butyric acid methyl ester(PC71BM) as active layers are used to fabricate polymer solar cells (PSCs), and a variety of post-treatments are employed to optimize the PSCs performance. A maximum power conversion efficiency (PCE) of 1.22% is achieved for the conventional configuration device based on P2, and the inverted configuration device of P2 is also prepared for comparison. The results show that the inverted P2 device exhibits a better PCE (1.47%) than that of the conventional device due to the TiO2 nanoparticles and the close energy alignment between the work function of the MoO3 and the HOMO energy levels, which facilitate a light absorption increase and improved charge transport.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: In this paper, we reported that ZnO nanoparticles (NPs) film modified with C60 pyrrolidine tris-acid ethyl ester (PyC60) was used as cathode buffer layer in inverted polymer solar cells. The resultant device with a blend of PTB7:PC71BM as photoactive materials exhibited an open-circuit voltage (Voc) of 0.753 V, a short-circuit current (Jsc) of 16.04 mA cm 2, a fill factor (FF) of 72.5%, and an overall power conversion efficiency (PCE) of 8.76%. It was higher than the control devices based on sole ZnO NPs film or ZnO: PyC60 hybrid film as cathode buffer layer. It was found that the morphology improvement of ZnO/PyC60 film contributed to reducing series loss and interfacial charge recombination. In addition, it improved the interfacial contact with photoactive layer. The results increased electron injection and collection efficiency, and improved FF.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Hybrid transparent conductive films (TCFs) with a sandwich structure composed of aluminum-doped zinc oxide (AZO) and Ag nanowires (AgNWs) were deposited on polyethylene terephthalate (PET) substrates. The AZO layers were prepared at room temperature by RF magnetron sputtering. The AgNWs were synthesized by a modified polyol method and inserted into the AZO layers. The optical properties and conductivity can be modified by the number of spin-coating cycles of an AgNWs suspension. Typically, an AZO/AgNW/AZO hybrid film exhibited an optical transmittance of 80.5%, a sheet resistance of 27.6 U sq 1 and an optical haze of 14.9%. The increase in optical haze caused by the silver nanowires may be beneficial for applications in solar cells. The hybrid films presented excellent flexible stability, showing only minor resistance changes and no surface cracks compared with pure AZO films. The AZO layers acted as the protecting layers that enhanced the adhesive and thermal stability of the hybrid films. The resulting hybrid TCFs with an AZO/ AgNW/AZO sandwich structure show potential applications in flexible electronics, energy storage and photovoltaic devices.
提交时间: 2017-05-02
摘要: Template-free synthesis of TiO2 architectures with controlled morphology evolution has been developed through solvothermal reaction in 1,4-dioxane. By simply varying the molar ratio of the concentrated HCl over Titanium isopropoxide [TTIP] from 0 to 5.0,
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Two novel conjugated donoreacceptor polymers were synthesized by combining anthracene donor and benzothiadiazole acceptor with two different side chains (conjugated and non-conjugated). Their ab- sorption spectroscopy, thermogravimetric analysis, electrochemical cyclic voltammetry, theoretical prediction, surface morphology, and photovoltaic performance were investigated. The resultant two- dimensional configuration showed good optical and electrochemical properties. By selectively intro- ducing branched conjugated side chains and non-conjugated linear side chains on the polymer back- bone, the highest occupied molecular orbital levels are low lying which results in an increased open circuit voltage for polymer solar cells. The open circuit voltage of 1.02 V in this work was among the highest value for anthracene-based polymer solar cells ever. Our results suggest a good way to regulate the molecular energy levels by selecting appropriate side chains.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Three-dimensional (3D) graphene networks are attracting ever-increasing attention in the field of energy storage because their unique architecture at macroscopic scales is beneficial for effective electron and ion transport. Herein, a novel interconnected 3D graphene mesh network (3D GMN) was successfully designed and fabricated by folded Ni meshes assisted chemical vapor deposition method. The structure parameters of 3D GMN can be controlled well by tuning the period of Ni mesh and the electroplating time. With the increase of the density of 3D GMN, the electrical conductivity of 3D GMN and the thermal conductivity of 3D GMN/epoxy composite are greatly improved compared to that of the 3D graphene foam. This 3D GMN enables the high capacity of 57 mA h g 1 in an aluminum ion battery at the ultra- high rate of 40C with capacity retention of 96.5% after 200 cycles.