Ultrasound-assisted Microwave Synthesis of White Fungus-like In2S3 and In2S3/Cu1.8Se Composite for CuIn(S, Se)2 Film

White fungus-like In2S3 microspheres and In2S3/Cu1.8Se composites were successfully synthesized via a facile ultrasound-assisted microwave method. The reaction temperature could be as low as 70 °C and the reaction time was very short. The In2S3 microspheres were constructed by nanoflakes and many cavities existed in the microspheres. In2S3/Cu1.8Se composite was synthesized using the asprepared In2S3 microspheres as the template. Introducing Cu1.8Se compound did not changed the basic morphology of the template. Through doctor blade coating-rapid sintering method, CuIn(S, Se)2 film was further fabricated. The as-prepared film was demonstrated to be flat and compact, which could be applied as chalcopyrite solar cell thin film.