Entropy-controlled fully reversible nanostructure formation of Ge on miscut vicinal Si(001) surfaces

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10414816" target="_blank" >RIV/00216208:11320/20:10414816 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14310/20:00116625

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=71TpXPgaZZ" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=71TpXPgaZZ</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.102.075420" target="_blank" >10.1103/PhysRevB.102.075420</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Entropy-controlled fully reversible nanostructure formation of Ge on miscut vicinal Si(001) surfaces

Popis výsledku v původním jazyce

Entropy effects substantially modify the growth of self-assembled Ge nanostructures on vicinal Si(001) surfaces, on which one-dimensional nanowire-like structures are formed. As shown by variable temperature scanning tunneling microscopy, these nanostructures are not only tunable in size and shape, but can be fully reversibly erased and reformed without changes in sizes and composition. This unprecedented behavior is caused by the strong free surface energy renormalization due to the large step entropy of vicinal surfaces that strongly increases with increasing temperature. This favors a planar two-dimensional surface at higher temperatures in thermodynamic equilibrium, whereas the nanostructured surface is the preferred low-temperature configuration. Taking the step entropy into account, the critical transition temperature between these surface states derived by free-energy minimization is shown to scale nearly linearly with the Ge coverage-in excellent agreement with the experiments. Most importantly, the nanowire sizes are found to be deterministically controlled by the Ge thickness and vicinal angle, independently of the growth or annealing conditions. Thus, highly reproducible structures with tunable nanogeometries and -dimensions are obtained, which opens promising avenues for device applications.

Název v anglickém jazyce

Entropy-controlled fully reversible nanostructure formation of Ge on miscut vicinal Si(001) surfaces

Popis výsledku anglicky

Entropy effects substantially modify the growth of self-assembled Ge nanostructures on vicinal Si(001) surfaces, on which one-dimensional nanowire-like structures are formed. As shown by variable temperature scanning tunneling microscopy, these nanostructures are not only tunable in size and shape, but can be fully reversibly erased and reformed without changes in sizes and composition. This unprecedented behavior is caused by the strong free surface energy renormalization due to the large step entropy of vicinal surfaces that strongly increases with increasing temperature. This favors a planar two-dimensional surface at higher temperatures in thermodynamic equilibrium, whereas the nanostructured surface is the preferred low-temperature configuration. Taking the step entropy into account, the critical transition temperature between these surface states derived by free-energy minimization is shown to scale nearly linearly with the Ge coverage-in excellent agreement with the experiments. Most importantly, the nanowire sizes are found to be deterministically controlled by the Ge thickness and vicinal angle, independently of the growth or annealing conditions. Thus, highly reproducible structures with tunable nanogeometries and -dimensions are obtained, which opens promising avenues for device applications.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review B

ISSN

2469-9950

e-ISSN

—

Svazek periodika

102

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

075420

Kód UT WoS článku

000557726800009

EID výsledku v databázi Scopus

2-s2.0-85090124638