RT Journal Article
T1 Strategies to unblock the n-GaAs surface when electrodepositing Bi from acidic solutions
A1 Prados Díaz, Alicia
A1 Ranchal Sánchez, Rocío
A1 Pérez García, Lucas
AB 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.
PB Pergamon-Elsevier Science Ltd.
SN 0013-4686
YR 2015
FD 2015-08-20
LK https://hdl.handle.net/20.500.14352/24196
UL https://hdl.handle.net/20.500.14352/24196
LA spa
NO ©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.
NO Ministerio de Economía y Competitividad (MINECO)
NO Ministerio de Educacion (Spain)
DS Docta Complutense
RD 9 abr 2025