Department of Chemistry (MC 111), University of Illinois at Chicago , Chicago, Illinois 60607, United States.
ACS Appl Mater Interfaces. 2014 Aug 13;6(15):12901-8. doi: 10.1021/am5028428. Epub 2014 Jul 8.
Bulk-heterojunction films composed of semiconductor nanoparticles blended with organic oligomers are of interest for photovoltaic and other applications. Cu2-XS nanoparticles were cluster beam deposited into thermally evaporated pentacene or quaterthiophene to create bulk-heterojunction thin films. The nanoparticle stoichiometry, morphology, and chemistry within these all-gas phase deposited films were characterized by X-ray photoelectron spectroscopy (XPS) and electron microscopy. Cu2-XS nanoparticles were (at most) only slightly copper-deficient with respect to Cu2S; ∼2.5 nm diameter, unoxidized Cu2-XS nanoparticles formed in both pentacene and quaterthiophene, as the matrix was not observed to impact the nanoparticle morphology or chemical structure. Cluster beam deposition allowed direct control of the nanoparticle stoichiometry and nanoparticle:organic ratio. Chemical states or Wagner plots were combined with other XPS data analysis strategies to determine the metal oxidation state, indicating that Cu(I) was predominant over Cu(II) in the Cu2-XS nanoparticles.
由半导体纳米粒子与有机低聚物混合组成的体异质结薄膜在光伏和其他应用中很有吸引力。Cu2-XS 纳米粒子通过团簇束沉积到热蒸发的并五苯或噻吩中，以形成体异质结薄膜。通过 X 射线光电子能谱 (XPS) 和电子显微镜对这些全气相沉积薄膜中的纳米颗粒化学计量、形态和化学性质进行了表征。与 Cu2S 相比，Cu2-XS 纳米颗粒（最多）只是略微缺铜；直径约为 2.5nm 的未氧化 Cu2-XS 纳米颗粒在并五苯和噻吩中均有形成，因为未观察到基质会影响纳米颗粒的形态或化学结构。团簇束沉积可以直接控制纳米颗粒的化学计量和纳米颗粒与有机物的比例。化学状态或 Wagner 图与其他 XPS 数据分析策略相结合，确定了金属氧化态，表明在 Cu2-XS 纳米颗粒中 Cu(I) 占主导地位，而 Cu(II) 则较少。
