Lifang Lu

Bio: Lifang Lu is an academic researcher from Beijing Jiaotong University. The author has contributed to research in topics: Thin film & Indium tin oxide. The author has an hindex of 6, co-authored 18 publications receiving 100 citations.

Effect of an Ultra-thin Molybdenum Trioxide Layer and Illumination Intensity on the Performance of Organic Photovoltaic Devices†

Abstract: The effect of an ultra-thin molybdenum trioxide (MoO3) layer thickness inserted between the indium tin oxide (ITO) substrate and copper phthalocyanine (CuPc) layer on the performance of organic pho...

Structure, Optical, and Magnetic Properties of Mn-doped ZnO Films Prepared by Sputtering

Abstract: The microstructural, optical, and magnetic properties and room-temperature photoluminescence (PL) of Mn-doped ZnO thin films were studied. The chemical compositions were examined by energy dispersive X-ray spectroscopy (EDS) and the charge state of Mn ions in the ZnO:Mn films was characterized by X-ray photoelectronic spectrometry (XPS). From the X-ray diffraction (XRD) data of the samples, it can be found that Mn doping does not change the orientation of ZnO thin films. All the films prepared have a wurtzite structure and grow mainly along the c-axis orientation. The grain size and the residual stress were calculated from the XRD results. The optical transmittance of the film decreases with the increase of manganese content in ZnO. The room-temperature photoluminescence of the films shows that the intensity of near band energy (NBE) emission depends strongly on the Mn content. The hysteresis behavior indicates that the films with the Mn content below 9at% are ferromagnetic at room temperature.

Enhanced pure red electroluminescence intensity of Eu(o-BBA)3(phen) by red dye co-doping and inorganic semiconductor as charge carrier function layer

Abstract: There is an emission peak at 494 nm in the electroluminescence (EL) of PVK [poly(n-vinylcarbazole)]: Eu(o-BBA)3(phen) besides PVK exciton emission and Eu3+ characteristic emissions. Both the peaking at 494 nm emission and PVK emission influenced the color purity of red emission from Eu(o-BBA)3(phen). In order to restrain these emissions and obtain high intensity red emission, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7,-tetramethyljulolidy-9-enyl)-4Hpyran (DCJTB) and Eu(o-BBA)3(phen) were co-doped in PVK solution and used as the active emission layer. The EL intensity of co-doped devices reached to 420 cd/m2 at 20 V driving voltage. The chromaticity coordinates of EL was invariable (x = 0.55, y = 0.36) with the increase of driving voltage. For further improvement of EL intensity, organic–inorganic hybrid devices (ITO/active emission layer/ZnS/Al) were fabricated. The EL intensity was increased by a factor of 2.5 [(420 cd/m2)/(168 cd/m2)] when the Eu complex was doped with an efficient dye DCJTB, and by a factor of ≈4 [(650 cd/m2)/(168 cd/m2)] when in addition ZnS layer was deposited on such an emitting layer prior to evaporation of the Al cathode.

Lanthanide luminescence for functional materials and bio-sciences

Abstract: Recent startling interest for lanthanide luminescence is stimulated by the continuously expanding need for luminescent materials meeting the stringent requirements of telecommunication, lighting, electroluminescent devices, (bio-)analytical sensors and bio-imaging set-ups. This critical review describes the latest developments in (i) the sensitization of near-infrared luminescence, (ii) “soft” luminescent materials (liquid crystals, ionic liquids, ionogels), (iii) electroluminescent materials for organic light emitting diodes, with emphasis on white light generation, and (iv) applications in luminescent bio-sensing and bio-imaging based on time-resolved detection and multiphoton excitation (500 references).

Status and Prospects of ZnO-Based Resistive Switching Memory Devices

Abstract: In the advancement of the semiconductor device technology, ZnO could be a prospective alternative than the other metal oxides for its versatility and huge applications in different aspects. In this review, a thorough overview on ZnO for the application of resistive switching memory (RRAM) devices has been conducted. Various efforts that have been made to investigate and modulate the switching characteristics of ZnO-based switching memory devices are discussed. The use of ZnO layer in different structure, the different types of filament formation, and the different types of switching including complementary switching are reported. By considering the huge interest of transparent devices, this review gives the concrete overview of the present status and prospects of transparent RRAM devices based on ZnO. ZnO-based RRAM can be used for flexible memory devices, which is also covered here. Another challenge in ZnO-based RRAM is that the realization of ultra-thin and low power devices. Nevertheless, ZnO not only offers decent memory properties but also has a unique potential to be used as multifunctional nonvolatile memory devices. The impact of electrode materials, metal doping, stack structures, transparency, and flexibility on resistive switching properties and switching parameters of ZnO-based resistive switching memory devices are briefly compared. This review also covers the different nanostructured-based emerging resistive switching memory devices for low power scalable devices. It may give a valuable insight on developing ZnO-based RRAM and also should encourage researchers to overcome the challenges.

Green Energy and Technology

Abstract: Climate change, environmental impact and the limited natural resources urge scientific research and novel technical solutions. The monograph series Green Energy and Technology serves as a publishing platform for scientific and technological approaches to "green" i.e. environmentally friendly and sustainable technologies. While a focus lies on energy and power supply, it also covers "green" solutions in industrial engineering and engineering design. Green Energy and Technology addresses researchers, advanced students, technical consultants as well as decision makers in industries and politics. Hence, the level of presentation spans from instructional to highly technical. **Indexed in Scopus**.

Tunable band gap energy of Mn-doped ZnO nanoparticles using the coprecipitation technique

Abstract: A simple coprecipitation technique was introduced to form manganese (Mn) doped on zinc oxide (ZnO) nanoparticles effectively. Based on our morphological studies, it was revealed that mean particle size was increased while bigger agglomeration of nanoparticles could be observed as the amount of concentration of Mn was increased. Interestingly, it was found that the position of the absorption spectra was shifted towards the lower wavelength (UV region) as correlated with the increasing of Mn dopants concentration into ZnO nanoparticles. This result inferred that optimum content of Mn doped into the ZnO nanoparticles was crucial in controlling the visible/UV-responsive of samples. In the present study, 3mol% of Mn dopants into the ZnO nanoparticles exhibited the better UV as well as visible light-responsive as compared to the other samples. The main reason might be attributed to the modification of electronic structure of ZnO nanoparticles via lattice doping of Mn ions into the lattice, whereas excessive Mn dopants doped on ZnO nanoparticles caused the strong UV-responsive due to the more 3d orbitals in the valence band.