Electrochemical growth and characterization of Cu2O:Na/ZnO heterojunctions for solar cells applications

Strain or Electronic Effects? – The influence of alkali metals on the bandgap of Cu2O

“…This corresponds to a more realistic doping level of 3% versus Cu which is reasonably close to typical dopant concentrations in experimentally relevant systems. [13,14,27,28] In line with our hypothesis we find only a very minor increase of the bandgap from 1.95 eV for pure Cu 2 O to 2.00 eV. This increase is independent from the choice of alkali metal (Figure 1c) and agrees qualitatively with experimental observations for slightly lower dopant levels.…”

“…The doping level of the 2x2x2 unit cell is reasonably close to that typically found in experimentally relevant systems where doping levels of the order of 1 at% have been reported in the case of Na doping. [13,14,27,28] Higher doping levels have been found to result in the formation of alkali metal oxide phases rather than substitution of Cu [11].…”

Improvement of the photocatalytic performance of ZnO thin films in the UV and sunlight range by Cu doping and additional coupling with Cu2O

“…The combination of two semiconductors forming a hybrid photocatalyst, where electrons are transferred to the CB of one semiconductor and holes to the VB of the other semiconductor at the interface, prevents charge recombination [21]. Most studies refer to the use of Cu 2 O/ZnO heterostructure films as hybrid photocatalysts in photovoltaic devices [22][23][24]. In addition, both techniques can exploit solar energy conversion by extending the absorption ability of the semiconductors to the visible region.…”

Synthesis and characterization of Mg-doped ZnO thin-films electrochemically grown on FTO substrates for optoelectronic applications

“…The broadening or blue shi of the E g was most likely caused by the so-called Burstein Moss effect resulted from the increase of the charges carrier density introduced by increasing the Mg doping. [50][51][52] The high charges carrier density lled the lowest states at the bottom of the conduction band. Since the Pauli principle prevents the double occupancy of states and the optical transitions are vertical, the electrons in the valence band require extra-energy to be excited to higherenergy states in the conduction band.…”