ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
This article describes the results of a surface morphology study of photodeposited thin film devices of Selenium by scanning force microscopy (SFM). First, the structures of the photodeposited films were investigated at device level dimensions of the order of visible wavelength. Specifically, ultrathin sinusoidal holographic gratings with spatial periods in the range 480–514 nm were visually identified from SFM nanograph images. Second, grain level structural investigation was performed using image processing techniques such as filtering and one- and two-dimensional Fourier transforms analysis. The variation of the surface grain structure was sampled across the Gaussian profiles of the laser photodeposited patterns. It was found that the random amorphous clustering at the perimeter of the deposited structures becomes progressively grainy towards the center, creating protrusions above the surface with trigonal Selenium (t-Se) crystalline features. Third, performing image enhancement analysis at high magnification—the nanometer level structure was investigated for amorphous Selenium (a-Se) and the laser thermally induced structural transformations of the a-Se films. It was found that the atomic solid-state structure of a-Se films, previously deduced only by indirect methods, consists mainly of a random mixture of Sex branched chains containing also a small concentration of imperfect ring structures characteristic of the α- and β-monoclinic phases. The triclinic crystalline phase (t-Se) was identified in the center of the laser overheated regions of the film Gaussian profile. The results enable us to conclude about the debate in the literature regarding the crystalline and amorphous structure of Selenium thin films. © 1995 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.359149
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