Ana-Maria LEPADATU1,*, Ionel STAVARACHE1, Catalin PALADE1, Adrian SLAV1, Valentin A. MARALOIU1, Ioana DASCALESCU1, Ovidiu COJOCARU1, Valentin S. TEODORESCU1,2, Toma STOICA1, Magdalena L. CIUREA1,2,*
Abstract. Nanocrystalline Si and Ge are of high interest for integrated Si photonics related to light emission, optical sensors, photodetectors, solar energy harvesting and conversion devices, and also for floating gate non-volatile memories (NVMs). In this review, we have focused on nanocrystalline porous Si (nc-PS) with extension to Si nanodots, and Ge nanocrystals (NCs)/quantum dots (QDs)/nanoparticles (NPs) embedded in oxides (SiO2, TiO2, HfO2, Al2O3). The great asset of nc-PS is its intense photoluminescence in VIS at room temperature (RT), while Ge NCs/NPs embedded in oxides show high photosensitivity in VISNIR-SWIR in the spectral photocurrent up to 1325 nm at RT. Ge NCs/NPs/QDs floating gate NVMs present high memory performance, the retention characteristics corresponding to the state of the art for NCs floating gate NVMs. We prove the relevance of controlling the preparation parameters for obtaining films with targeted photoluminescence, photosensitivity and charge storage properties for applications, e.g. VIS-NIR-SWIR optical sensors and photodetectors, and electronic and photoelectric NVMs. We evidence the correlation of preparation conditions, morphology, composition and crystalline structure with optical, electrical, photoelectrical and charge storage properties and also evidence the contribution of quantum confinement effect, localized states and trapping centers. Keywords: nanocrystalline porous Si, Si nanodots, Ge nanocrystals embedded in oxides, VISNIR-SWIR sensors, floating gate non-volatile memories
DOI 10.56082/annalsarsciphyschem.2022.1.53
1 National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania
2 Academy of Romanian Scientists, 54 Splaiul Independentei, 050094 Bucuresti, Romania
*Correspondence: ciurea@infim.ro, lepadatu@infim.ro
PUBLISHED in Annals of the Academy of Romanian Scientists Series on Physics and Chemistry, Volume 7, No1