Colloidal nanocrystal synthesis of alkaline earth metal sulfides for solution-processed solar cell contact layers

Abstract To gain insight into the applicability as building blocks for optoelectronic device development, alkaline earth metal sulfides are investigated. MgS, CaS, SrS, and BaS have been systematically synthesized as colloidal particles in olelyamine. The particle sizes range from around 819 nm for MgS to 12.8 nm for CaS, 25.0 nm for SrS, and 21.6 nm for BaS. The heat-up synthesis uses commerically available precursors without complicated procedures. The structural and optical properties are investigated with X-ray diffraction, spectroscopic ellipsometry, UV–vis spectrophotometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy.