Method for determining LUMO value and HOMO value of semiconductor nano-crystals through utilizing cyclic voltammetry

Abstract

The invention relates to a method for determining the LUMO value and the HOMO value of semiconductor nano-crystals through utilizing cyclic voltammetry. The semiconductor nano-crystals are dispersed in a solvent to form a semiconductor nano-crystal solution, the surface of a work electrode (6) is coated with the semiconductor nano-crystal solution in a drop manner to form a film, the electrochemical performances of the semiconductor nano-crystals are tested under the protection of an inert gas by means of the three-electrode system of an electrochemical work station, and the potential in the initial position of an oxidation reduction reaction of the nano-crystals is extracted, so the LUMO value, the HOMO value and the forbidden bandwidth value of the semiconductor nano-crystals are obtained through calculating in order to realize the accurate determination of the energy band structure of the semiconductor nano-crystals, and the test result obtained in the invention is smaller than the result obtained through using absorption spectrometry. The drop coating manner in the method provided by the invention makes the semiconductor nano-crystals to form the film on the surface of the work electrode, so the experimental material adoption amount is reduced; and the protection of the inert gas avoids the instability of the semiconductor nano-crystals, so the determination of the energy band structures of various semiconductor nano-crystals can be realized.

Description

technical field [0001] The invention belongs to the field of performance testing of nanomaterials, and in particular relates to a method for measuring the LUMO value and HOMO value of semiconductor nanocrystals by cyclic voltammetry. Background technique [0002] Due to its large specific surface area, efficient carrier transport capability, optical, electrical and magnetic properties different from bulk materials and ordinary molecules, semiconductor nanocrystals are widely used in solar cells, information storage and light-emitting devices. The field has broad application prospects and has become the focus of the majority of scientific research workers. The energy level structure of semiconductor nanocrystals includes LUMO (Lowest Unoccupied Molecular Orbital), which is the lowest energy level orbital that does not occupy electrons, and HOMO (Highest Occupied Molecular Orbital), that is, the highest energy level orbital that has occupied electrons. It has an important imp...

AI Technical Summary

Problems solved by technology

However, because nanocrystals are relatively active, unstable, and sensitive to the environment, it is difficult to test the position of their band edges.

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