Aluminum doping of CuInSe₂ synthesized by solution process and its effect on structure, morphology, and bandgap tuning

Abstract

Al‐doped CuInSe2 material is prepared by a low‐cost wet chemical process. The key properties of Al‐doped CuInSe2 as a successful solar cell material are investigated, such as crystal structure, morphology, optical properties, and bandgap. In situ X‐ray diffraction measurements indicate that the doping of Al has induced noticeable lattice distortion. The material shows excellent thermal stability up to 600 °C annealing temperature. By increasing the Al‐doping concentration, the crystal unit‐cell parameter of the material becomes smaller and the change of crystal structure leads to an increase of the grain size and surface roughness. The bandgap of Al‐doped CuInSe2 can be continuously tuned in a range of 1.07–1.67 eV as Al/(Al + In) content ratio varies from 0 to 0.49. Finally, the effect mechanism on the properties of CuInSe2 after Al doping is discussed based on the ionic radius, crystal structure, and bonding state.

Characterization and photoelectrochemical properties of CICS thin films grown via an electrodeposition route

“…Additionally, In has a low melting point of about 156 C compared to other metals of CIS compounds, which creates a narrow process window for realizing elevated crystal growth and high efficiency. 7 As a result of this drawback, an appropriate means of impurity ions doped CIS thin lms may be enable to overcome the cost of rare materials. Commonly, ion alkali dopants (Na + , K + ) are employed in CIGS solar cells in order to improve the performance of the device.…”