Structural and Electronic Properties of Barium Silicide on Si(100)

Growth and characterization of group-III impurity-doped semiconducting BaSi2 films grown by molecular beam epitaxy

“…After cleaning the Si(111) substrate at 850°C for 30 min in ultrahigh vacuum (UHV), a well-developed 7 × 7 reflection high-energy electron diffraction (RHEED) pattern was confirmed. RHEED patterns were observed along the [1][2][3][4][5][6][7][8][9][10] MBE growth of Ga-or In-doped BaSi 2 films was carried out as follows. First, a 20-nm-thick BaSi 2 epitaxial film was grown on Si(111) at 550°C by reactive deposition epitaxy (RDE) and used as a template for BaSi 2 overlayers.…”

“…We have developed an epitaxial growth technique for BaSi 2 and Ba 1 − x Sr x Si 2 on Si(111) substrates by molecular beam epitaxy (MBE) using a BaSi 2 template [5][6][7]. The E g value of BaSi 2 is approximately 1.3 eV [2,[8][9][10], and α for this material reaches 10 5 cm − 1 at 1.5 eV [2], which is approximately two orders of magnitude higher than that of Si. Furthermore, the E g value can be increased up to approximately 1.4 eV, matching the solar spectrum, by replacing half of the Ba atoms in BaSi 2 with isoelectric Sr atoms [11].…”

Optical and electrical properties of semiconducting BaSi2 thin films on Si substrates grown by molecular beam epitaxy

“…BaSi 2 consists of Si and Ba, which are abundant in resources, and its band gap is reported to be 1.1 -1.3 eV at room temperature (RT). These band gap values have been obtained from the temperature dependence of resistivity and diffuse reflectance spectra on the polycrystalline bulk BaSi 2 , and also from scanning tunneling spectroscopy on a-few-monolayerthick BaSi 2 on Si [1,2]. Recent first-principles calculation predicted that an optical absorption (OA) coefficient a of BaSi 2 is expected to reach 10 5 cm À 1 at 1.5 eV [3], but a has not yet been obtained experimentally.…”

Semiconductor(BaSi2)/metal(CoSi2) Schottky-barrier structures epitaxially grown on Si(111) substrates by molecular beam epitaxy

“…This value is approximately two orders of magnitude larger than that of Si, and has been attributed to large values of dipole matrix elements across the gap due to a mixture of Ba-pd and Si-spd states [6]. In addition, the band gap of BaSi 2 was found to reach the ideal value of approximately 1.4 eV matching the solar spectrum by replacing half of the Ba atoms with isoelectric Sr atoms [7][8][9][10][11]. We therefore believe that BaSi 2 is very promising as a material for high-efficiency thin-film solar cells.…”