Quantum regulation of Ge nanodot state by controlling barrier of the interface layer

Quantized energy in Ge nanodots aligned over oxidized Si surfaces could be regulated by modifying an interface atomic layer. The confining potential was evaluated from dot-size dependent energy shift of the ground state of confined holes, which revealed that epitaxial nanodots showed a lower confining potential barrier than nonepitaxial ones. The present results provide a new way to tune quantized energy levels of Ge nanodots not only by their size but also by interface condition.