Effects of europium substitution for In on structure and photoelectric properties of CuIn1−xEuxTe2

•Novel europium doped CuIn1−xEuxTe2.•Potential application for devices and solar cells.•A mixture of hopping and variable range hopping conductivity mechanism.

The structures and optical and electric properties of europium doped CuIn1−xEuxTe2 have been studied systematically using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectrum (EDS), ultraviolet and visible spectrophotometer (UV–vis), and standard four-probe method. The studies reveal that the minor europium doping into CuIn1−xEuxTe2 could still stabilize the chalcopyrite structure in a solid solution of x=0.1. The lattice parameters are going up with increasing the content of europium in CuIn1−xEuxTe2 due to the size effect at In site. The structural refinement confirms that Eu partly substitutes for In and occupies the 4b crystal position. SEM morphologies show that the europium doping into CuIn1−xEuxTe2 can fine the grains from the largely agglomerated state to the uniformly separated state. The electrical resistivities of single phase CuIn1−xEuxTe2 follow a mixture model of hopping conductivity and variable range hopping conductivity. The absorption band-gaps of CuIn1−xEuxTe2 at room temperature tend to increase with increasing Eu content. CuIn1−xEuxTe2 might be a good candidate for photovoltaic cell.

Graphical abstractCuIn0.9Eu0.1Te2 follows a mixture of hopping conductivity and variable range hopping conductivity mechanism.Figure optionsDownload full-size imageDownload as PowerPoint slide