Application of abnormally high sputtering rate of PbTe(Te) single crystals during inductively coupled argon plasma treatment for fabrication of nanostructures

Abstract

This paper reports the investigations of the sputtering process of (111) oriented single crystals of PbTe with excess tellurium (4 at.%) in RF high-density low-pressure inductively coupled argon plasma. An increase of 1.6 times the sputtering rate of lead telluride in comparison with the classical case of single-crystal state with a slight deviation from stoichiometry is shown and the explanation of the results is carried out based on the analysis of the crystal point defects. The active sputtering is used in a new approach to form lead telluride nanostructures on oxidized Si substrates via the vapour-liquid-solid (VLS) redeposition mechanism, and the fabrication of PbTe nanocones, nanocubes and nanowires with various geometrical parameters is demonstrated.

Variation of Surface Nanostructures on (100) PbS Single Crystals during Argon Plasma Treatment

“…The very low etching rate at an energy of 25 eV in this case may be due to the difficult sputtering of the thin, partially oxidized near-surface layer formed during mechanical polishing and chemical cleaning. Thus, an important feature of the experiment performed with E i = 25 eV (in contrast with previous experiments on (111)-oriented PbX films [22][23][24]) was the low sputtering rate of the (100) PbS surface, which led to a smaller amount of sputtered material above the treated surface. It is noteworthy that the surface temperature also plays an important role in the processes of nanostructuring during plasma treatment, which determines the mechanism of nanostructure formation.…”

“…During interaction of ions with the surface, different surface nanostructure formation mechanisms are possible [13][14][15][16][17][18][19], which makes ion and ion-plasma techniques an important tool for surface nanostructuring. We used binary compounds of PbX and ternary solid solutions based on them as examples to show that varying inductively coupled argon plasma treatment condition enables the formation of micro-and nanostructures [20][21][22][23][24][25][26][27]. These nanostructures exhibit various morphologies on the surface 2 of 11 of single crystals and mono-and polycrystalline films of lead chalcogenides, which can influence the optical properties of modified systems.…”

“…Specifically, the sputtered material was redeposited on a heated surface in the form of "building blocks" consisting of both binary PbX molecules and atomic lead, which formed nano-and microstructures on the surface. In our previous studies [20][21][22][23][24][25][26][27], only a certain set of conditions were considered for the ion-plasma treatment, leading to specific types of nanostructures. Alternatively, in the present work for the first time, various plasma treatment conditions have been employed in the ion energy range of 25-200 eV, and the physical processes occurring during surface modification have been analyzed using the crystals of one specific material: PbS.…”

Surface nanostructuring of CuIn1−xGaxSe2films using argon plasma treatment

“…The plasma treatment of the CIGS/Mo/glass samples was carried out in radio-frequency inductively coupled plasma (RF ICP) in accordance with our well established experimental technique used for the nanostructuring of lead chalcogenide films [10,14]. We used inert argon plasma discharge.…”

Plasma-assisted surface nanostructuring of epitaxial Pb1−x Sn x Te (0 ≤ x ≤ 1) films

“…However, the reported 'bottom-up' nanostructure formation methods are high-temperature and expensive, and a search for more economically viable and accessible approaches to the Pb 1−x Sn x Te nanostructuring actively continues. In a series of our recent papers [5][6][7][8][9], we have proposed a new 'top-down' approach to the surface nanostructuring using inductively coupled argon plasma treatment, which we have applied to a wide range of chalcogenide materials, allowing the fabrication, among others, of the PbTe nanowires on Si substrate [7] and of the vertical cylindrical CuIn 1−x Ga x Se 2 nanostructures [8]. Previously, we have already started the experimental work aimed to carry over this approach to the Pb 1−x Sn x Te material, which resulted in successful nanostructuring for polycrystalline Pb 1−x Sn x Te films [10], and we have started the studies of the singlecrystal epitaxial Pb 1−x Sn x Te films with the investigations of their sputtering rates [11].…”