Electronic structures of semiconducting alkaline-earth metal silicides

Formation of BaSi2 heterojunction solar cells using transparent MoOx hole transport layers

“…[13][14][15] The large absorption coefficient originates from the band structure of BaSi 2 , where the localized Ba d-like states form flat energy bands in the conduction band. [14][15][16] One of the most attractive features of BaSi 2 is that both the high absorption coefficient and large minority-carrier diffusion length can be utilized. This feature facilitates the collection of photogenerated carriers in an external circuit.…”

Potential variations around grain boundaries in impurity-doped BaSi2 epitaxial films evaluated by Kelvin probe force microscopy

“…[1][2][3][4] Large absorption coefficients come from the band structure of BaSi 2 , where the localized Ba d-like states form flat energy bands in the conduction band. [5][6][7] Minority-carrier properties, such as a long minority-carrier diffusion length (ca.10 lm) 8,9 and a long minority-carrier lifetime (ca.10 ls), [10][11][12] in a-axis-oriented undoped n-type BaSi 2 epitaxial films spurred interest in this material. One of the striking features of this material is the fact that both large minority-carrier diffusion length and large absorption coefficient are available.…”

“…41 There are two crystallographically inequivalent sites for Ba (Ba (1) and Ba (2) ) and three inequivalent sites for Si (Si (3) , Si (4) , and Si (5) ) in the unit cell of BaSi 2 . The unit cell contains eight formula units.…”

“…The unit cell contains eight formula units. Therefore, the stoichiometric description of the unit cell is Ba 8 Si 16 , and the atoms are distributed over 4Ba (1) , 4Ba (2) , 4Si (3) , 4Si (4) , and 8Si (5) . Hereafter, we describe the compound, for example, as Ba 8 Sb (3) Si 15 , where one of the Si (3) sites of Ba 8 Si 16 is substituted with Sb.…”

“…The formation energies of the Ba 8 Si 16 substituted with In or Ga were calculated by using the first-principles method. 40 In the case of Ga doping, 40 40 Hence, we chose one Ba (1) site for Ba substitution, and one Si (3) site for Si substitution in this article although there are another Ba site, Ba (2) , and the other two Si sites, Si (4) and Si (5) , in Ba 8 Si 16 .…”