Method for preparing photoanode of co-sensitized quantum dot solar cell

Abstract

The invention discloses a method for preparing a photoanode of a co-sensitized quantum dot solar cell. According to the photoanode, the pre-synthesis of CdSe and Zn-Cu-In-Se quantum dot sensitizers with a complementary effect of light absorption intensity in different wavelengths is carried out, and a surface is modified by using different bifunctional ligands. A surface-ligand induced self-assembly strategy is used to orderly deposit modified quantum dots in a mesoporous TiO2 photoanode film, a multi-component quantum dot co-sensitized photoanode is prepared, and a QDSC (quantum dot solar cell) is assembled. The complementary and synergy effects between quantum dot component units are used, therefore, a quantum dot band gap is matched with solar photon energy, the spectral absorption range is broadened without affecting a photogenerated electron injection rate, and the light absorption capability is enhanced. A heterogenous interface in the photoanode and the charge transfer kineticsof a liquid-solid interface between electrolytes are improved. A new method for obtaining high photocurrent and photoelectric conversion efficiency is established, and the efficiency of the developedQDCC is larger than 12%.

Description

[0001] The invention relates to a method for preparing a photoanode of a quantum dot sensitized solar cell. The photoanode is prepared by pre-synthesizing quantum dot sensitizers with complementary effects in light absorption intensities in different wave bands, and using a surface ligand-induced self-assembly strategy to prepare multi-components Quantum dot co-sensitized photoanode. The quantum dot-sensitized solar cell assembled based on the photoanode prepared by this method obtained high photocurrent and photoelectric conversion efficiency. Background technique [0002] Quantum Dot Sensitized Solar Cell (QDSC) is a photovoltaic device that uses inorganic semiconductor nanomaterials (also known as quantum dots) as light harvesting agents for photoelectric conversion. Its typical structure and working principle are as follows: figure 1 shown. Due to the simple and low-cost preparation process of quantum dots, coupled with the high light absorption coefficient and the low de...

AI Technical Summary

Problems solved by technology

However, the mutual restraint of the comprehensive properties of single quantum dot sensitizers limits the development of QDSCs

A variety of single quantum dots (including CdS / CdSe, CdTe / CdSe, CdSe x Te 1-x and CuInS 2 and Zn-Cu-In-Se alloy structure QD) are used to assemble batteries, and their photoelectric conversion efficiency is still far from the theoretical efficiency.

Although Zn-Cu-In-Se alloy quantum dots extend the absorption range to the near-infrared region of about 1000nm, the short-circuit current value (25-26mA / cm 2 ) is much lower than the theoretical value, the main reason is that it is difficult for a single sensitizer to take into account the properties of narrow band gap, high conduction band energy and high molar extinction coefficient, so in a wide light absorption range, high electron injection rate and high light absorption There is a contradiction between the intensity

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