Nanostructurale nature of the porous GaAs layer formed on p+-GaAs substrate by electrochemical anodization
A porous GaAs layer has been formed by electrochemical anodization in HF based solution on extremely doped p-type GaAs substrate. Porous nature of the elaborated sample has been evidenced by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Nanostructurale nature of the porous layer has been demonstrated by X-ray diffraction analysis (XRD) and confirmed by photoluminescence spectroscopy (PL).
Morphology and strongly enhanced photoluminescence of porous GaAs layers made by anodic etching
Abstract Porous GaAs layers obtained by electrochemical etching were investigated using SEM, TEM and optical methods. The morphology, chemical composition and photoluminescence of porous layers were investigated. It was shown that porous layer consists of Ga 2 O 3 , As 2 O 3 , As 2 O 5 and GaAs submicron grains. Photoluminescence spectra of investigated porous layers consist of “infrared” and “green” spectral structures. The observed short wavelength photoluminescence (PL) at 590–778 nm of the porous layer is explained by the quantum size effect in the GaAs nanocrystals.
History of Amateurism in Men's Intercollegiate Athletics: The Continuance of a 19th-Century Anachronism in America
Claiming that American intercollegiate athletics are amateur at the end of the 20th century is an anachronism, for colleges in the 19th century took on professional characteristics. The upper-class British concept of amateurism did not work effectively in a more egalitarian and achievement-oriented American society. Hypocrisy resulted when colleges claimed amateurism while accepting such professional practices as hiring professional coaches, allowing athletes to play summer baseball for money, and paying athletes through grants-in-aid. Attempts to preserve amateurism, such as the Graham Plan in the 1930s and the Sanity Code in the 1940s and 1950s, yielded to the professional spirit. Thus, while Americans had generally rejected the upper-class British social hierarchy that fostered amateurism, they retained the name amateur, continuing the hypocrisy that had begun in the previous century.