Microstructure and electrical transport in electrodeposited Bi films

Abstract

The semimetal character of bismuth and its large photon absorbing power make of this element the most suitable absorber material for X-ray low temperature detectors. This application requires coatings of Bi with thicknesses and properties that only electrodeposition methods may achieve.Although there are studies on electrodeposition of bismuth for these detectors and other devices, the process is not straightforward and has not been sufficiently studied in terms of the desired final properties, neither the effect of different parameters is well known or easily reproduced. This work reports the influence of two different electrolytes, of the deposition method, and of heating and stirring on the structure, microstructure and transport properties of bismuth films. Typically, rhombohedral Bi is obtained upon electrodeposition with very good crystallinity, and some crystal preferential orientation, while significant empirical correlations are found among electrochemical parameters, microstructure, and resistivity. Such correlation allows the identification of the deposition parameters for coatings that yield the optimal functional properties.

Early-Stage Growth Mechanism and Synthesis Conditions-Dependent Morphology of Nanocrystalline Bi Films Electrodeposited from Perchlorate Electrolyte

“…The formation of granular films during the electrodeposition in electrolytes, containing bismuth nitrate pentahydrate and nitric acid as the main components, has also been observed in work [5]. However, the grain morphology is somewhat different for our case.…”

“…However, the grain morphology is somewhat different for our case. Here, the grains are more densely packed than in work [5], where the Bi films have high porosity and roughness. The results of the study of the dependence of the Bi films porosity on the deposition duration (1-30 s) for the main studied samples are presented in Figure 6.…”

“…This chemical element has highly unusual physical properties including thermoelectrical, electronic, and magnetic ones [1][2][3][4]. It is a semimetal with a high anisotropic Fermi surface, and low and very large carrier densities and mobilities, respectively [5]. For example, nanostructured thin Bi films revealed exotic magneto-electronic properties which make them appealing materials for spintronic applications [6][7][8], displayed large positive magnetoresistance [9], and Bi-modified electrodes due to their catalytic properties and mechanical stability were used for electrochemical sensors instead of poisonous mercury electrodes [10][11][12][13][14].…”

“…For example, nanostructured thin Bi films revealed exotic magneto-electronic properties which make them appealing materials for spintronic applications [6][7][8], displayed large positive magnetoresistance [9], and Bi-modified electrodes due to their catalytic properties and mechanical stability were used for electrochemical sensors instead of poisonous mercury electrodes [10][11][12][13][14]. From the point of view of condensed matter research and other significant applications, especially in the films form, have been applied to test several quantum confinement phenomena [5,[15][16][17]. Bi-based sensitive radiation detectors, such as microcalorimeters demonstrate good X-ray absorption because of Bi's large atomic number and very low heat capacity [5,[18][19][20][21].…”

“…From the point of view of condensed matter research and other significant applications, especially in the films form, have been applied to test several quantum confinement phenomena [5,[15][16][17]. Bi-based sensitive radiation detectors, such as microcalorimeters demonstrate good X-ray absorption because of Bi's large atomic number and very low heat capacity [5,[18][19][20][21]. Uses of Bi-based composites and coatings offer a very applicable alternative to the lead protection against proton radiation due to much more environmentally friendly Bi [22,23].…”