Effect of using a high-purity Fe source on the transport properties of p-type β-FeSi2 grown by molecular-beam epitaxy

Abstract

Intentionally undoped p-type β-FeSi2 thin films were grown on Si(111) substrates by molecular-beam epitaxy using low-purity (4N) and high-purity (5N) Fe sources to investigate the effect of using a high-purity Fe source on the electrical properties of β-FeSi2. The hole mobility increased and the hole density decreased greatly as the annealing temperature and time were increased, particularly for the β-FeSi2 films produced using 5N-Fe. The observed temperature dependence of the hole mobility was reproduced well by considering various carrier scattering mechanisms due to acoustic-phonon, polar-optical phonon, nonpolar-optical phonon, and ionized impurities.

Synthesis and characterization of β-phase iron silicide nano-particles by chemical reduction

“…Almost in all cases of theoretical calculation of band diagram they have reported undoped ␤-FeSi 2 to be p-type [1,6,7,[31][32][33][34] as the Fermi level lies very close to valence band maxima whereas for experimental cases most of them reported undoped ␤-FeSi 2 to be p-type [30,[35][36][37][38]41] and few reported it to be n-type [35,39,40]. The Hall measurement of the ␤-FeSi 2 thick pallet sample in room temperature shows that it has p-type conductivity with average Hall coefficient of R H = +2.74 m 3 /C which agrees quite well with that of theoretical estimation as well as experimental determination of conduction type of undoped ␤-FeSi 2 .…”

“…The energy band structure has been theoretically calculated in several literatures [1,6,7,[31][32][33][34] and the conduction type has been determined theoretically [30,[35][36][37][38][39][40][41] as well as experimentally in various literatures for undoped ␤-FeSi 2 . Almost in all cases of theoretical calculation of band diagram they have reported undoped ␤-FeSi 2 to be p-type [1,6,7,[31][32][33][34] as the Fermi level lies very close to valence band maxima whereas for experimental cases most of them reported undoped ␤-FeSi 2 to be p-type [30,[35][36][37][38]41] and few reported it to be n-type [35,39,40].…”

Study on the n-β-FeSi2/p-Si solar cells under different illuminated directions

“…The parameters of ␤-FeSi 2 thin film are adopted from Refs. [3,[12][13][14][15][16][17]. The default crystalline-silicon numerical model in the program is employed for the silicon substrate.…”

Lifetime and diffusion length of photogenerated minority carriers in single-crystalline n-type β-FeSi2 bulk

“…15,16 These large mobilities of hole can be well explained by means of classical scattering mechanisms, namely, by the acoustic and nonpolar phonon modes as well as by the charged and neutral impurity scatterings. 17,18 However, the hole mobility in p-type ␤-FeSi 2 bulk has been reported to be in the range of 10-20 cm 2 / V s. [19][20][21] We think that this discrepancy comes from surface damaged regions in ␤-FeSi 2 crystals. The short decay time observed in Fig.…”