Preparation and Structural Characterization of Thin Films of CuInS2 by Sintering Colloidally Synthesized Nanoparticles at Moderate Temperature

Copper indium disulfide nanoparticles continue attracting attention as absorber material in light harvesting devices. The preparation of thin films by deposition of this material from colloidal solution remains challenging. Typically, colloidal semiconductor nanoparticles are surrounded by long organic ligand molecules which are required to stabilize the particles during synthesis. A common way to obtain conductive thin films is the development of ligand exchange procedures that need to be applied prior to film deposition. However, in the case of copper indium disulfide nanoparticles, appropriate procedures are still missing. Therefore, an alternative approach is investigated herein. Colloidal copper indium disulfide nanoparticles are synthesized and deposited on substrates. Instead of applying a ligand exchange procedure, thermal removal of the ligands and sintering of the inorganic film are explored. Results on the preparation of the nanoparticle films, their structural investigation, and conductivity measurements are reported.