Growth, optical and electrical properties of Ca2Si film grown on Si(111) and Mg2Si/Si (111) substrates

Formation and properties of p–i–n diodes based on hydrogenated amorphous silicon with embedded CrSi₂, Mg₂Si and Ca₂Si nanocrystallites for energy conversion applications

“…For Ca2Si(Mg) sample the transmittance edge at 0.8 eV is not exactly coincided with transmittance edge of "ITO T before CrSi2" curve (Fig. 5 c) due to the optical band gap of Ca2Si could be smaller than the electrical one (1.02 eV [8]). We only propose the real strong absorption in Ca2Si layers of grown samples beginning at energies smaller than 0.8 eV.…”

“…3 b, line "Ca") new peaks have also appeared: 5.2 eV (interband transition), 10.5 eV (surface plasmon) and 14.0 eV (bulk plasmon) without any contribution of bulk Si plasmon for amorphous Si (17.8 eV). It is known that Ca2Si has surface plasmon of 9.6 -10.4 eV and bulk plasmon of 13.4-14.0 eV [8]. So, we can speak about formation of near continuous Ca2Si film on the first stage of Ca deposition at 150 o C. After deposition of Ca-Si multilayer structure changes in AES (Fig.…”

“…5 c). It is known that band gap of CrSi2 film is about 0.35 eV [1], for Mg2Si is about 0.76 eV [2], but for Ca2Si the first experimental data offered a band gap value of about 1.02 eV [8] from Hall temperature measurements. Since the quantity of Cr, Mg and Ca silicides is small in grown multilayers (smaller than 30 nm), a real absorbance in silicides can occur only at absorption coefficient higher than 510 5 cm -1 and photon energies higher than 1.0 eV.…”

Investigation of structural, elastic, and lattice-dynamical properties of Ca2Si, Ca2Ge, and Ca2Sn based on first-principles density functional theory

“…Specifically, Mg 2 Si and its solid solutions have been extensively studied as candidates for use in high-performance thermoelectrics with a dimensional figure-of merit (ZT) > 1 [3]. Compared to Mg 2 Si and its solid solutions, there have been a limited number of studies on Ca 2 X, mainly due to the considerable difficulties in handling Ca [6][7][8][9][10][11][12][13][14][15]. However, Ca 2 Si is comprised of environmentally friendly, non-toxic, inexpensive elements found in high abundance on Earth.…”

Formation and optical properties of semiconducting thick Ca silicide films and Si/CaxSi/Si heterostructures on Si(111) substrate

“…In situ temperature Hall measurements data [1] have shown that thin Ca 2 Si layer grown on 2D Mg 2 Si template on Si(111) substrate at (120-130) °C is characterized by 1.02 eV of energy band gap value which precisely corresponds to Ca 2 Si quasiparticle band structure calculations [2]. Complex study of thin Ca 2 Si layers growth at 120 o C and their embedding in a silicon has been carried out on Si(111) and Mg 2 Si template with different thickness [3].…”