Quasi van der Waals epitaxy (QvdWE) of III-V semiconductors on two-dimensional layered material, such as graphene, is discussed. Layered materials are used as a lattice mismatch/thermal expansion coefficient mismatch-relieving layer to integrate III-V semiconductors on any arbitrary substrates. In this chapter, the epitaxial growth of both III–V nanowires and thin films on two-dimensional layered materials is presented. Also, the growth challenges of thin film on two-dimensional materials using QvdWE are discussed through density functional theory calculations. Furthermore, optoelectronic devices of III-V semiconductors integrated on two-dimensional layered material based on QvdWE are overviewed to prove the future potential and importance of such type of epitaxy.
Part of the book: Two-dimensional Materials
In 2007, a Nobel Prize is awarded to Dr. Albert Fert and Peter Grünberg for their contribution in giant magnetoresistance (GMR) effect. The magnetic head based on GMR effect has significantly increased the storage density in the hard disk drive (HDD) and brought the coming of the digital age. Besides, the rapid development of GMR sensor has opened a wide and promising range of applications, including the aspects in automobile, traffic monitor, biomedicine, and space, etc. As continuously extending the market, it needs GMR sensor with much lower cost, smaller size, higher sensitivity, and compatibility with the CMOS technology. In light of that, we give a review about the recent progress of the MR effect in MnxGe1−x system, which refers to the material growth and magnetic and MR property. Through engineering the MnxGe1−x structure, it could realize the transition from negative to positive MR, geometric-enhanced giant MR, and electric-field controlled MR. The fact of well-designed MR effect and high compatibility with Si technology brings a high potential and advantage for fabricating MnxGe1−x-based MR sensors, which could be widely used in magnetic head and biomedical sensors, among others, with the superiority of much lower manufacturing cost, lower power dissipation, higher integration density, and higher sensitivity.
Part of the book: Magnetic Sensors