Ke Tang

Bio: Ke Tang is an academic researcher from Shanghai University. The author has contributed to research in topics: Diamond & Sputter deposition. The author has an hindex of 13, co-authored 131 publications receiving 579 citations. Previous affiliations of Ke Tang include Tianjin University & City University of New York.

The effects of substrate temperature on properties of B and Ga co-doped ZnO thin films grown by RF magnetron sputtering

Abstract: In this work, B and Ga co-doped ZnO (BGZO) films were fabricated by RF magnetron sputtering method. The effects of substrate temperature on the electrical, optical, structural and morphological properties of B and Ga co-doped ZnO films were investigated. XRD results revealed that deposited films were textured along c-axis and maintain wurtzite crystalline symmetry. As substrate temperature increased up to 200 °C, the film crystallinity was improved and the crystallite sizes became larger. At the substrate temperature of 200 °C, the films showed lower resistivity, higher Hall mobility and higher optical band gap. It was also observed that all films showed high transparency in the visible range (400–800 nm), which did not change obviously with the substrate temperature.

Micro‐/Nanostructured Mechanical Metamaterials

Abstract: Mechanical properties of materials have long been one of the most fundamental and studied areas of materials science for a myriad of applications. Recently, mechanical metamaterials have been shown to possess extraordinary effective properties, such as negative dynamic modulus and/or density, phononic bandgaps, superior thermoelectric properties, and high specific energy absorption. To obtain such materials on appropriate length scales to enable novel mechanical devices, it is often necessary to effectively design and fabricate micro-/nano- structured materials. In this Review, various aspects of the micro-/nano-structured materials as mechanical metamaterials, potential tools for their multidimensional fabrication, and selected methods for their structural and performance characterization are described, as well as some prospects for the future developments in this exciting and emerging field.

RaoP-Type ZnO Materials: Theory, Growth, Properties, and Devices

Abstract: Abstract In the past 10 years, ZnO as a semiconductor has attracted considerable attention due to its unique properties, such as high electron mobility, wide and direct band gap and large exciton binding energy. ZnO has been considered a promising material for optoelectronic device applications, and the fabrications of high quality p-type ZnO and p–n junction are the key steps to realize these applications. However, the reliable p-type doping of the material remains a major challenge because of the self-compensation from native donor defects (V O and Zn i ) and/or hydrogen incorporation. Considerable efforts have been made to obtain p-type ZnO by doping different elements with various techniques. Remarkable progresses have been achieved, both theoretically and experimentally. In this paper, we discuss p-type ZnO materials: theory, growth, properties and devices, comprehensively. We first discuss the native defects in ZnO. Among the native defects in ZnO, V Zn and O i act as acceptors. We then present the theory of p-type doping in ZnO, and summarize the growth techniques for p-type ZnO and the properties of p-type ZnO materials. Theoretically, the principles of selection of p-type dopant, codoping method and X Zn –2V Zn acceptor model are introduced. Experimentally, besides the intrinsic p-type ZnO grown at O-rich ambient, p-type ZnO (MgZnO) materials have been prepared by various techniques using Group-I, IV and V elements. We pay a special attention to the band gap of p-type ZnO by band-gap engineering and room temperature ferromagnetism observed in p-type ZnO. Finally, we summarize the devices based on p-type ZnO materials.

Photoelectric Detectors Based on Inorganic p-Type Semiconductor Materials.

Abstract: Photoelectric detectors are the central part of modern photodetection systems with numerous commercial and scientific applications. p-Type semiconductor materials play important roles in optoelectronic devices. Photodetectors based on p-type semiconductor materials have attracted a great deal of attention in recent years because of their unique properties. Here, a comprehensive summary of the recent progress mainly on photodetectors based on inorganic p-type semiconductor materials is presented. Various structures, including photoconductors, phototransistors, homojunctions, heterojunctions, p-i-n junctions, and metal-semiconductor junctions of photodetectors based on inorganic p-type semiconductor materials, are discussed and summarized. Perspectives and an outlook, highlighting the promising future directions of this research field, are also given.