Thermodynamic and Kinetic Factors Controlling the Bi Incorporation in III-V Thin Films Grown by Metal-organic Vapor Phase Epitaxy
Author | : Yingxin Guan |
Publisher | : |
Total Pages | : 0 |
Release | : 2017 |
ISBN-10 | : OCLC:1023436811 |
ISBN-13 | : |
Rating | : 4/5 (11 Downloads) |
Book excerpt: Bi-containing III-V alloys have been proposed as alternative candidates for near and mid-infrared optoelectronic applications in recent years stimulated by the large bandgap energy reduction arising from the Bi addition into the III-V matrix. Metal-organic vapor phase epitaxy (MOVPE) of Bi-containing III-V alloys has been explored covering from the studies on its fundamental growth kinetics to the heterostructure designs containing III-V-Bi layers. As a group V element with a large covalent radius, Bi incorporation in the III-V matrix is thermodynamically unflavored and subjected to phase-separation during the growth process. Low growth temperatures are required to slow down the surface kinetics that lead to the Bi droplets formation. At such low growth temperatures, the Bi incorporation in III-V systems is expected to be mainly controlled by a sequence of chemical reactions, which may be difficult to predict due to the large number of possible reaction pathways involved in the metal-organic precursor at the gas phase and on the surface. In this study, the equilibrium Bi solubility in the III-V semiconductors was explored to reveal the thermodynamic limitation for Bi incorporation and illustrate the possible approaches to enhance the Bi solubility through tuning the Gibbs free energy of the system by the epitaxial stain or additional element incorporation. MOVPE growth was also carried out systematically to study the important kinetic processes involved in the MOVPE growth of GaAs1-xBix and In1-yGayAs1-xBix. This research enriched our knowledge of the fundamental thermodynamics and kinetics associated with the Bi-containing III-Vs and their MOVPE growth, revealed practical approaches to enhance the Bi solubility in III-V matrix, and supported the future semiconductor heterostructure design utilizing the Bi-containing III-V alloys.