Strategies to unblock the n-GaAs surface when electrodepositing Bi from acidic solutions



Downloads per month over past year

Prados Díaz, Alicia and Ranchal Sánchez, Rocío and Pérez García, Lucas (2015) Strategies to unblock the n-GaAs surface when electrodepositing Bi from acidic solutions. Electrochimica Acta, 174 . pp. 264-272. ISSN 0013-4686

[thumbnail of Ranchal 01 postprint + EMBARGO 20_08_2017.pdf]

Official URL:


Bismuth ultra-thin films grown on n-GaAs electrodes via electrodeposition are porous due to a blockade of the electrode surface caused by adsorbed hydrogen when using acidic electrolytes. In this study, we discuss the existence of two sources of hydrogen adsorption and e propose different routes to unblock the n-GaAs surface in order to improve Bi films compactness. Firstly, we demonstrate that increasing the electrolyte temperature provides ompact yet polycrystalline Bi films. Cyclic voltammetry scans indicate that this low crystal quality might be a result of the incorporation ofBi hydroxides within the Bi film as a result of the temperature increase. Secondly, we have illuminated the semiconductor surface to take advantage of photogenerated holes. These photocarriers oxidize the adsorbed hydrogen nblocking the surface, but also create pits at the substrate surface that degrade the Bi/GaAs interface and prevent an epitaxial growth. Finally, we show that performing a cyclic voltammetry scan before electrodeposition enables the growth of compact Bi ultra-thin films of high crystallinity on semiconductor substrates with a doping level low enough to perform transport measurements.

Item Type:Article
Additional Information:

©Pergamon-Elsevier Science Ltd..
We acknowledge partial financial support of this work by Spanish Ministerio de Economía y Competitividad (project MAT2011-28751-C02). Alicia Prados acknowledges financial support from Ministerio de Educación of Spain (FPU program) and acknowledges the useful discussions on this work with Dr. Ángela Llavona.

Uncontrolled Keywords:Situ infrared-spectroscopy; Electrochemical formation; Schottky barriers; P-gaas; Semiconductors; Adsorption; Evolution; Cathodes; States; Gold
Subjects:Sciences > Physics > Materials
Sciences > Physics > Solid state physics
ID Code:33533
Deposited On:09 Oct 2015 15:59
Last Modified:20 Aug 2017 23:01

Origin of downloads

Repository Staff Only: item control page