Papers by Author: Toshikazu Kurihara

Abstract: The annihilation behavior of positronium in N and P type porous silicon is investigated via positron annihilation lifetime (PAL) and positronium time-of-flight (Ps-TOF) measurements. The result shows the N type sample has smaller positronium annihilation fraction and more interconnected pores. The microstructure of Rapid Thermal Oxidation (RTO) treated N type porous silicon also studied using PAL spectroscopy, and the relationship between its photoluminescence properties and porous structure was discussed.

Abstract: We prepared a series of mesoporous silica films to study the structural information of ordered pores by positronium Time of Flight (Ps-TOF) spectroscopy. By changing the ratio of surfactant to silicon source, the pore structure is tuned. Results show that once ordered pores are formed, clear Ps TOF peak is observed. And the film with less distributed pore geometry leads to a narrowed Ps TOF peak.