Physico-Chemical nanomaterials science

Application of InSe (0001) surface as template for indium deposited 0D nanosystem formation
P.V. Galiy1, T.M. Nenchuk1, A. Ciszewski2, P. Mazur2, O.R. Dveriy3, Ya.M. Buzhuk1
1 Electronics and Computer Technology Department, Ivan Franko Lviv National University, 50 Dragomanov Street, Lviv, 79005, Ukraine.
E-mail: galiy@electronics.lnu.edu.ua
2 Institute of Experimental Physics, University of Wrocław, pl. Maxa Borna 9, 50-204 Wrocław, Poland.
3 Chair of Electromechanics and Electronics, National Academy of Land Forces, 32 Geroiv Majdanu Street, Lviv, 79012, Ukraine

2D layered semiconductor InSe is the object of modern research suitable for functional nanoscale devices applications, particularly, for the future super-fast electronics. Template directed self-assembly is among the ways to the successful fabrication of nanosystems. Due to InSe intrinsic bulk anisotropy its (0001) surface might be just easily obtained by cleavage even in UHV which makes it suitable as a template for obtaining nanosystems with reduced dimension in situ.
The study of In deposition with further nanosystems formation was conducted using scanning tunneling microscopy/spectroscopy (STM/STS) data from Omicron NanoTechnology STM/AFM System. Thermal evaporator EFM-3 was applied for In deposition in UHV. The studies included statistical analysis of STM data from large areas by standard roughness analysis tools from the WSxМ software taking into account the distribution of pixels' height of the image depending on the degree of In deposition, as well as detailed analysis of high-resolution STM images.
Some quantity of nuclei in In/InSe nanosystem appears at the initial stages of In deposition. We can observe 0D islands with extreme peakness (kurtosis parameter) on the surface without visible signs of ordering. The next indium deposition leads to the smoothing of surface relief with the appearance of self-similar large areas with a small difference in height. We were able to achieve the formation of nanosized 0D triangular shaped structures in a result of the solid state dewetting process by surface heating above the indium melting point. The STS spectra analyses show good correlation between the In coverage and the reduction of InSe band gap as determined from spatially averaged current voltage curves, as well as the qualitative transition to the formation of the local metallic phase of indium.