Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties

Beilstein Journal of Nanotechnology

Marina Vega-González¹  Víctor Manuel Castaño-Meneses²  Omar Martínez-Alvarez³  Laura Susana Acosta-Torres⁴  Javier de la Fuente-Hernández⁴  Ma. Concepción Arenas-Arrocena⁴  José Santos-Cruz⁵  Priscilla Vasthi Quintana-Ramirez⁶ 

[1] Centro de Geociencias, UNAM, 76230, Querétaro, México;Departamento de Ingeniería Molecular de Materiales, CFATA, UNAM, 76230, Querétaro, México;Departamento de Ingeniería en Energía, Universidad Politécnica de Guanajuato, 38483, Guanajuato, México;Escuela Nacional de Estudios Superiores Unidad León, UNAM, Boulevard UNAM No. 2011 Predio el Saucillo y el Potrero, 36969, León Guanajuato, México;Facultad de Química, Materiales Universidad Autónoma de Querétaro, 76010, Querétaro, México;Posgrado en Ciencia e Ingeniería de Materiales, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, 76230, Querétaro, México;

关键词: abundant materials in the crust of Earth;    electrical resistance;    nanocrystals;    nanodisks;    non-toxic semiconductors;    optical band gap;    phase transition;    photocurrent;   

DOI  :  10.3762/bjnano.5.166

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown