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Graphene–zinc oxide (G–ZnO) nanocomposites were prepared through a hydrothermal approach and used as electron acceptors in poly-(3-hexylthiophene) (P3HT)-based bulk-heterojunction organic solar cells (OSCs). The blended film, which was a mixture of different weight ratios of P3HT and G–ZnO, was applied as the active layer in the OSC device. The power conversion efficiency (PCE) increases first and then decreases with the increase in G–ZnO content in the blended films. The device containing 15 wt% (ratio to P3HT) of G–ZnO shows the best performance with a PCE of 0.98%, an open-circuit voltage of 0.81 V and a short-circuit current density of 4.92 mA cm−2. The impact of the intrinsic mechanism on the characteristics of the OSCs under the illumination condition is discussed. [ABSTRACT FROM AUTHOR]

Antireflection (AR) film is a widely used technology to enhance the performance of photovoltaic devices that require transparent electrodes in the photovoltaic industry. At present, several AR films including monolayer MgF2 or multilayered composite films, textured polydimethylsiloxane (PDMS) and porous SiO2 have been successfully applied due to their excellent properties. Nevertheless, all of the above-mentioned AR films have some minor drawbacks to overcome, for instance, the cost or thermal durability. Herein, we report a cost-effective and low-temperature method to fabricate a mesoporous aluminum oxide (meso-Al2O3) layer as the AR coating with high thermal durability, which will meet the fabrication condition of various photovoltaic devices. Briefly, the process begins at magnetron sputtering a compact Al2O3 film, which shows no AR effect, followed by a hot water treatment at 80 °C to turn the compact film into a mesoporous film with graded-index and AR effect. The application of meso-Al2O3 AR film enhances the maximum transmittance of our laboratory-used fluorine-doped tin oxide (FTO) from 84% to 89%, which is in good agreement with our theoretical simulation named graded-index approximation. Taking perovskite solar cells (PSCs) as an example, planar PSCs with meso-Al2O3 AR film deliver excellent photon conversion efficiency of 21.5%, which is higher than that of cells without meso-Al2O3 AR film (20.9%). [ABSTRACT FROM AUTHOR]

In this paper, layered ZnO nanowall networks were directly grown on Al substrates using a hydrothermal method without predepositing seed layers. The individual ZnO nanowalls with a thickness of several nanometers and a size of several hundred nanometers were (002) surface dominated, in which the preferential growth direction of ZnO was suppressed. White electroluminescence devices were fabricated based on Au/polymethylmethacrylate/ZnOnanowall (metal-insulator-semiconductor) structures. The chromaticity coordinate of the electroluminescence spectrum for the optimal device was calculated as (0.27, 0.34), which is close to (0.33, 0.33) of standard white light. [ABSTRACT FROM AUTHOR]

A TiO2 thin film was deposited on a Nb : SrTiO3 substrate by pulsed laser deposition to form an Ag/TiO2/Nb : SrTiO3/In device. The bipolar resistive switching (RS) effect of this device was investigated. The current–voltage characteristics exhibited pronounced and stable bipolar RS features. The device could be switched to a low resistance state (LRS) at forward voltage and returned to a high resistance state (HRS) at reverse voltage, and the RS ratio RHRS/RLRS reached up to 2 × 103 at a read voltage of −0.5 V. Moreover, the RS ratio could be adjusted by changing the maximum value of the forward or reverse voltage, which shows promise for multilevel memories. These results are discussed by considering carrier injection-trapped/detrapped process of the heterostructure and show high potential for nonvolatile memory applications. [ABSTRACT FROM AUTHOR]