Solar cell device based on strain type heterojunction quantum dots and manufacturing method thereof

Abstract

The invention relates to a solar cell device based on strain type heterojunction quantum dots, in particular to a manufacturing method of the solar cell device, and belongs to the field of solar cell materials. The cell device comprises at least two Ge / Si quantum dot structural layers growing on a doped silicon substrate. The Ge / Si quantum dot structural layers are composed of Si film layers including Ge quantum dots with the diameter ranging from 2 nm to 7 nm, the thickness of the innermost Si film layer ranges from 2 nm to 4 nm, and the thickness gradually increases layer by layer. The outermost quantum dot structural layer is a SiO2 coverage film layer filling the clearances of the quantum dots, and a quantum dot array filling film multi-layer structure is formed. A layer of silicon doped layer protection film with the thickness ranging from 10 nm to 20 nm grows outside the coverage film layer, and electrodes grow on the outer surface of the silicon doped layer and the outer surface of the silicon substrate. The energy band range of the device is expanded to be between 0.4 eV to 0.22 eV, the corresponding conversion efficiency ranges from 55 percent to 57 percent, and can be improved by more than seven percent by being compared with that of the prior art, and the photoelectric conversion efficiency of a solar cell is obviously improved.

Description

technical field [0001] The invention relates to a solar cell, in particular to a solar cell device based on strained heterojunction quantum dots, and to a preparation method thereof, belonging to the field of solar cell materials. Background technique [0002] Solar energy is an inexhaustible renewable and clean energy source on the earth. The efficient use of solar energy is one of the core topics that research institutions and industries are focusing on at present, including solar cells based on photoelectric conversion effects. devices and applications. Quantum dot solar cell technology is a new generation technology of current solar cell research. [0003] Solar cells based on semiconductor quantum dots have the following characteristics: the size of quantum dots is in the scale of several nanometers, often called "artificial atoms", the energy band structure is affected by the three-dimensional quantum size effect, the energy level is discontinuous, and the scale of qu...

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Problems solved by technology

However, the strain effect and its effective utilization in solar cells have not been reported in the above-mentioned patent documents and currently known related documents.

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