Donor and acceptor energy levels in impurity Sb-, In-, Ag- and Cu-doped semiconducting BaSi2 thin films for device applications

In this article donor and acceptor energy levels due to the impurity Sb-, In-, Ag- and Cu-doped BaSi2 films grown in the ultra-high vacuum, UHV molecular beam epitaxy (MBE) were investigated. The temperature dependence of electron or hole concentrations indicated that the acceptor energy levels in impurity, In-, and Ag-doped BaSi2 are 86 meV, and 126 meV, respectively, and the donor energy levels in impurity Cu-, and Sb-doped BaSi2 are 35 meV, and 47 meV respectively. Two shallow donor energy levels of 47 meV and 35 meV respectively due to Sb and Cu impurity atoms in n-type BaSi2 were successfully identified for the device applications including photovoltaic.