Current-induced nanogap formation and graphitization in boron-doped diamond films

A high-current annealing technique is used to fabricate nanogaps and hybrid diamond/graphite structures in boron-doped nanocrystalline diamond films. Nanometer-sized gaps down to ?1?nm are produced using a feedback-controlled current annealing procedure. The nanogaps are characterized using scanning electron microscopy and electronic transport...

Increased carrier generation rate in Si nanocrystals in SiO2 investigated by induced absorption

We report on investigations of optical generation of carriers in Si nanocrystals embedded in SiO2 matrix by time-resolved induced absorption technique. Results obtained for excitation below and above twice the bandgap energy h??<?2Eg and h??>?2Eg show very similar decay characteristics (within ?resolution ? 100 fs). When intensity of the signal...

Electronic coupling of colloidal CdSe nanocrystals monitored by thin-film positron-electron momentum density methods

The effect of temperature controlled annealing on the confined valence electron states in CdSe nanocrystal arrays, deposited as thin films, was studied using two-dimensional angular correlation of annihilation radiation. A reduction in the intensity by ?35% was observed in a feature of the positron annihilation spectrum upon removal of the...

Formation and stability of rocksalt ZnO nanocrystals in MgO

Coimplantation of Zn and O ions into a single crystalline MgO and subsequent thermal annealing were applied in the synthesis of ZnO nanocrystals. Electron microscopy showed that rocksalt instead of wurtzite ZnO stabilizes for relatively large nanocrystals up to ~15?nm, resulting from its small lattice mismatch with MgO of ~1.7%. The vacancies...