Well-dispersed CuInSe2 nanoplates and nanoplates-ink-coated thin films for photovoltaic application by a triethylene glycol based solution process

Single-phase and well-dispersed CuInSe2 nanoplates were synthesized by a facile, ambient pressure solution chemical route using triethylene glycol as solvent, copper(II) chloride, indium(III) chloride and selenium powder as precursors, ethylenediamine as assisting agent and polyvinylpyrrolidone as capping agent. Structure and growing morphology of the products synthesized with and without polyvinylpyrrolidone addition were compared by TEM, XRD and SAED. The well-dispersed CuInSe2 nanoplates were applied to prepare ethanol-based colloidal ink and then deposit flat and highly crystallographic oriented CuInSe2 thin films by layer-by-layer dip-coating ink and then annealing at 500–580  °C in Ar atmosphere. I–V characteristics of the PV test devices with the ink-coated CuInSe2 light-absorbing layers were evaluated.

► CuInSe2 thin films with (112) orientation were prepared by nanoplates ink coating.
► Annealing at 580 °C in Ar led to high chalcopyrite crystallization of thin films.
► Fill factor and energy conversion efficiency reached 36% and 0.18%, respectively.