Oriented-aggregation of organic organization: Morphology-controllable synthesis, surface photovoltage spectroscopy and morphology-dependent optical property

Abstract

Assembled ZnQ 2·2H 2O microstructures, such as microsheet, sandwich-like structure and hexangular microflake, have been successfully prepared in CTAB microemulsion system through the stacking of ZnQ 2·2H 2O molecules and oriented aggregation of ZnQ 2·2H 2O original building blocks. Controlled experiments demonstrated that the morphologies of building block and final product could be readily tuned by reaction parameters, and a formation mechanism, involving re-precipitation, growth and oriented aggregation process, has been proposed on the basis of time-dependent experimental results. The obtained products were carefully characterized by X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), transmission electron microscope (TEM), field-emission scanning electron microscope (FESEM), FT-IR spectrum, UV–vis spectrum and photoluminescence (PL) spectrum. The surface photovoltage (SPV) of the obtained ZnQ 2·2H 2O microstructures was investigated by means of surface photovoltage spectroscopy (SPS) and field-induced surface photovoltage spectroscopy (FISPS). The SPS and FISPS revealed that the photogenerated charges of ZnQ 2·2H 2O could be separated distinctly and ZnQ 2·2H 2O possessed p-type semiconductor characteristics, respectively. Furthermore, UV–vis and PL spectra evidenced the optical properties of ZnQ 2·2H 2O were sensitive to its microstructure or morphology.