Broad spectrum-absorption quantum dot-sensitized broad-band semiconductor optical anode

Abstract

The invention provides a broad spectrum-absorption quantum dot-sensitized broad-band semiconductor optical anode and a preparation method thereof. A variety of narrow-band semiconductor quantum dots are coated on the surface of a broad-band semiconductor film electrode; the semiconductor quantum dots are superposed from the surface of a broad-band semiconductor in turn from the inside to the outside; the positions of conduction bands of the quantum dots are higher than that of the broad-band semiconductor and are risen in turn from the inside to the outside; the widths of forbidden bands of the quantum dots are between 0.9 to 2.6 eV and are reduced in turn from the inside to the outside; and the width of a forbidden band of at least one type of quantum dots is below 1.2 eV. In the broad spectrum-absorption quantum dot-sensitized broad-band semiconductor optical anode, the coverage rate of the quantum dots on the surface of the broad-band semiconductor optical anode is high, the quantum dots are distributed uniformly, surface defect states are fewer, the strong absorption of a broad spectrum can be realized, and the electron-hole separation, the transfer and the injection of optical electrons to the broad-band semiconductor are effectively realized, so the anode has positive significance for effectively improving the photoelectric conversion efficiency of a solar cell. The broad spectrum-absorption quantum dot-sensitized broad-band semiconductor optical anode can not only serve as the optical anode of a photoelectrochemical solar cell, but also serve as the optical anode ofa solar photochemical reaction.

Description

technical field [0001] The invention belongs to the technical field of solar energy utilization, in particular to the research field of solar photoelectrochemical cells based on quantum dot sensitized semiconductor photoanodes. technical background [0002] Dye-sensitized nanocrystalline solar cells (DSSCs) have the characteristics of low cost and simple process, and have attracted extensive attention from researchers from various countries since their invention. So far, their photoelectric conversion efficiency has reached 12%. In order to further reduce the cost of solar cells and improve their performance, many researchers are committed to developing low-cost and high-efficiency organic and inorganic dyes, among which inorganic semiconductor quantum dots (QDs) have become a research hotspot. The size effect of QDs enables people to adjust the spectral response range of solar cells by controlling their grain size; the high extinction coefficient of QDs allows people to use...

AI Technical Summary

Problems solved by technology

However, the photoelectric conversion efficiency of quantum dot-sensitized solar cells (QDSSCs) is still low compared with conventional dye-sensitized solar cells

One of the main reasons is that the reported quantum dot-sensitized semiconductor photoanodes have narrow light absorption range and low light absorption efficiency.

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