Visible light emission from Si materials

<title>Air optical breakdown on silicon as a novel method to fabricate photoluminescent Si-based nanostructures</title>

“…It seems that the mechanism of surface treatment in our experiments is similar in many respects to that of the electric spark processing, which was also used for the fabrication of Si-based nanostructured layer [11][12][13][14] . The spark-treated silicon also contained 10-500 nm holes and pores and consisted of silicon nanocrystals embedded in SiO 2 matrix (the presence of nanometer-size crystals was confirmed by Transmission Electron Microscopy studies 13 ).…”

“…The modifications wer attributed to pulsed ion bombardment of silicon surfaces, which led to a flash evaporation of the target material and its recrystallization during the off-times. Furthermore, the nanostructured layers fabricated by the electric spark processing in pure oxygen also exhibited 1.9 eV signals 11,12,14 , though they were relatively weak and fast-degrading 14 . However, the origin of these signals is still under debate.…”

“…However, detailed analysis of similar 1.9 eV signals and their properties in the case of spark-processed silicon does not confirm this assumption 13,14 . Other possible mechanism is a radiative recombination between quantum confined states in the nanoscale particles 1 , which was involved to explain some properties of the 1.9 eV component in the case of spark-processed silicon 12 . In any case, a clear identification of the PL mechanism requires further detailed study of mechanical, structural and PL properties of the deposited and annealed films.…”

“…The search of methods for the production of visible light-emission from Si-based materials becomes currently a great task and a subject of numerous studies (see, e.g., Refs. [1][2][3][4][5][6][7][8][9][10][11][12][13][14].…”

“…Using this method, nanostructured areas exhibiting PL in red (1.65 eV) and green (2.2 eV) were patterned, but the method required a preliminary deposition of the amorphous film, which made it rather expensive. Another possible approach is the processing of a silicon wafer by an electric spark [11][12][13][14] . Here, a silicon wafer is used as a cathode in a plasma-assisted process, in which unipolar discharges between two electrodes ionize the gaseous environment and accelerate the generated ions toward the silicon surface transforming it to a nanostructured Sibased layer.…”