Tuning Electrodeposition Conditions towards the Formation of Smooth Bi2Se3Thin Films

Bismuth selenide (Bi2Se3) is a semiconductor presenting two distinct crystalline phases with distinct bandgap and interesting optical, thermoelectric and topological electronic properties. In this work, thin films were grown by electrodeposition under constant potential onto silicon (100) substrate. It is shown that under an optimum set of deposition parameters, very smooth and thick films can be obtained. Such smoothness of the samples is highly desirable for future devices applications. Structural characterization of the samples indicates a majority of a metastable orthorhombic phase, while successively traces of rhombohedral and amorphous phases were detected. On the other hand, morphological characterization evidences the formation of compact, uniform and smooth layers. A full recrystallization to the rhombohedral structure can be achieved by using short time and low temperature thermal treatments.