TY - JOUR A1 - Quintana-Ramirez, Priscilla Vasthi A1 - Arenas-Arrocena, Ma. Concepción A1 - Santos-Cruz, José A1 - Vega-González, Marina A1 - Martínez-Alvarez, Omar A1 - Castaño-Meneses, Víctor Manuel A1 - Acosta-Torres, Laura Susana A1 - de la Fuente-Hernández, Javier T1 - Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties JF - Beilstein Journal of Nanotechnology PY - 2014/// VL - 5 SP - 1542 EP - 1552 SN - 2190-4286 DO - 10.3762/bjnano.5.166 PB - Beilstein-Institut JA - Beilstein J. Nanotechnol. UR - https://doi.org/10.3762/bjnano.5.166 KW - abundant materials in the crust of Earth KW - electrical resistance KW - nanocrystals KW - nanodisks KW - non-toxic semiconductors KW - optical band gap KW - phase transition KW - photocurrent N2 - Copper sulfide is a promising p-type inorganic semiconductor for optoelectronic devices such as solar cells, due its small band gap energy and its electrical properties. In this work nanocrystalline copper sulfide (CuxS), with two stoichiometric ratios (x = 2, 1.8) was obtained by one-pot synthesis at 220, 230, 240 and 260 °C in an organic solvent and amorphous CuxS was obtained in aqueous solution. Nanoparticle-like nucleation centers are formed at lower temperatures (220 °C), mixtures of morphologies (nanorods, nanodisks and nanoprisms) are seen at 230 and 240 °C, in which the nanodisks are predominant, while big hexagonal/prismatic crystals are obtained at 260 °C according to TEM results. A mixture of chalcocite and digenite phases was found at 230 and 240 °C, while a clear transition to a pure digenite phase was seen at 260 °C. The evolution of morphology and transition of phases is consistent to the electrical, optical, and morphological properties of the copper sulfide. In fact, digenite Cu1.8S is less resistive (346 Ω/sq) and has a lower energy band gap (1.6 eV) than chalcocite Cu2S (5.72 × 105 Ω/sq, 1.87 eV). Low resistivity was also obtained in CuxS synthesized in aqueous solution, despite its amorphous structure. All CuxS products could be promising for optoelectronic applications. ER -