Quantum dot and dye co-sensitization solar battery and preparation method thereof

Abstract

The invention relates to a dye sensitization solar battery, particularly a quantum dot and dye co-sensitization solar battery and a preparation method thereof. According to the invention, dye and quantum dots are sensitized in a photoanode and a photocathode respectively so as to enable visible light and infrared light to be absorbed in the two electrodes respectively; the sensitization solar battery includes the photoanode, the photocathode and an electrolyte arranged therebetween, wherein the photoanode consists of a n-shaped semi-conductor TiO2 and dye molecules adsorbed to the surface of the n-shaped semi-conductor TiO2; the photocathode consists of p-type quantum dots; and the electrolyte is obtained by dissolving Na2S, elementary substance S and sodium hydroxide in deionized water. According to the invention, as rays with different wavelengths are provided with different penetrating capabilities, dye is used to absorb visible light with less wavelength in the photoanode, and then quantum dots with less bend gap are used for absorbing transmitted near-infrared and infrared light, and as a result, sunlight can be absorbed and transformed more effectively and widely.

Description

technical field [0001] The invention relates to a dye-sensitized solar cell (Dye-sensitized Solar Cells), and in particular to a p-n type sensitized solar cell co-sensitized by quantum dots and dyes. Background technique [0002] Compared with traditional silicon cells, dye-sensitized solar cells (DSSCs) have a simple manufacturing process, low cost, and can be made into translucent and flexible devices, which have broad application prospects; in 1991, Swiss scientists Gr?tzel and others first used Nanotechnology has increased the conversion efficiency of dye-sensitized solar cells to 7%. Since then, dye-sensitized solar cells have developed rapidly; traditional dye-sensitized solar cells include photoanodes, counter electrodes and electrolytes. After the dye absorbs light, the photogenerated electrons are injected into the n-type semiconductor (TiO 2 , ZnO), the electrons return to the counter electrode through the external circuit to reduce the electrolyte, and the reduce...

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Problems solved by technology

After the dye absorbs light, the photogenerated electrons are injected into the n-type semiconductor (TiO 2 , ZnO), the electrons return to the counter electrode through the external circuit to reduce the electrolyte, and the reduced electrolyte diffuses to the photoanode to inject electrons into the dye to complete a cycle; traditional dye-sensitized solar cells use n-type semiconductors, which are adsorbed on the photoanode The dye absorbs light, and the opposite electrode only plays a role in catalyzing the electrolyte reduction reaction. After continuous development, the photoelectric conversion efficiency of dye-sensitized solar cells has reached 12% in the laboratory. Since the quantum efficiency of dyes is close to the limit, traditional structural cells However, dyes can only absorb visible light with a wavelength of less than 800nm, and infrared light, which accounts for more than 40% of solar energy, cannot be used. On the contrary, quantum dots have the advantages of adjustable band gap and multiple excitations. There is greater flexibility and controllability in the absorption spectrum. Combining quantum dots and dyes may achieve full-spectrum absorption, thereby improving the photoelectric conversion efficiency of the battery; Chinese patent CN 102157270A discloses a quantum dot dye-sensitized solar Cells, sensitize dyes and quantum dots to the photoanode to improve the absorption of incident light; (Shalom, M et al. J. Phys. Chem. Lett. 2010, 1, 1134-1138), introduce quantum dots To the photoanode of dye-sensitized solar cells, although it is possible to extend the absorption spectrum, it is difficult to truly realize the synergistic effect of the two because the existence of quantum dots affects the injection rate of dye photogenerated electrons into titanium dioxide.

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