Anisotropic MOF-on-MOF Growth of Isostructural Multilayer Metal–Organic Framework Heterostructures

Isostructural MOFs with similar crystallographic parameter are easily available for MOF-on-MOF growth and possible to form core–shell structure by isotropic growth. However, due to well-matched cell lattice, selective growth in isostructural MOF heterostructures remains a great challenge for engineering atypical MOF heterostructures. Herein, an anisotropic MOF-on-MOF growth strategy was developed to structure a range of multilayer sandwich-like ZIF-L heterostructures via stacking isostructural ZIF-L-Zn and ZIF-L-Co alternately with three-, five-, seven-, and more layer structures. Moreover, these heterostructures with highly designable feature were fantastic precursors for fabricating derivatives with tunable magnetic and catalytic properties. Such strategy explores a novel way of achieving anisotropic MOF-on-MOF growth between isostructural MOFs and opens up new horizons for regulating the properties by MOF modular assembly in versatile functional nanocomposites.

Crystallographic Parameter and Optical Absorption Measurement of CuInSe2 Thin Films for Solar Cells

Thin films CuInSe2(CIS) cells have been fabricated by the electro chemical method. Some of the physical properties such as lattice parameter, crystal structure and grain size of CuInSe2(CIS) films with different Cu/In ratios ( 0.50-1.1) were determined using X-ray diffractornetry. The surface morphology with different Cu/In ratios was studied using a scanning electron microscope. The SEM studies on these films showed that the grain size increases the Cu/In ratios increases from 0.49 to 1.1. The variation of the band gap with different Cu/In ratio was determined from optical absorption measurements. The results showed that the band gap decreases as the Cu/In ratio increases over the considered range of composition. Key words: Thin films, Lattice Parameter , Optical Absorption, grain size