Using photoelectron spectroscopy techniques (XPS/UPS) conduction and valence band offsets at (6 at:% Fe doped Zn S)/Cu2O heterojunction were calculated, giving _EC = e V and _EV = e V, respectively.
An improvement over undoped-Zn S/Cu2O heterojunction was demonstrated.
A successful K N co-doping in Cu2O was finally demonstrated.
A possibility to precisely control the dopant concentration and Fermi energy level position in Cu2O, thereby controlling the occupation of states within the band gap is an important requirement if Cu2O is to be useful in low price PV and PEC applications.
1–4 μm thick Zn S: Fe films of high optical quality with Fe content up to 9 at:% were made on sapphire and silicon using vapor deposition at room temperature.
Well-isolated optical absorption peaks were observed with iron concentrations up to 4 at:%, despite a high density of twin defects in the cubic crystal structure.Also some other peaks of Si, O are present due to the glass substrate.X-ray diffraction pattern of as-deposited indium doped Zn S thin films were studied.Using this method, extreme levels of doping were achieved as evidenced by a 350me V shift in the Fermi level towards the valence band maximum (VBM).The robustness of the nitrogen implanted samples was tested by exposing them to atmospheric contaminants, and elevated temperatures.K was in-situ deposited on a clean polycrystalline Cu2O surface.With increasing K concentration up to 8:7 at:%, the valence band maximum (VBM) shifted by 225me V to higher binding energies as determined by photoelectron spectroscopy.The X-ray pattern of the as deposited Zn S and In0.4Zn0.6S show a broad peak that confirms the amorphous nature of the film.But the In0.8Zn0.2S thin film is crystalline as X-ray of it shows five peaks at different 2theta position.Cu2O samples were made by annealing and controlled oxidation of Cu metal foils.A robust p-type doping of Cu2O using low/medium energy ion implantation was demonstrated.