Gainp/gaas/inganas/ge four-junction solar cell and preparation method thereof

Abstract

The invention provides a GaInP / GaAs / InGaNAs / Ge four-junction solar cell, comprising a Si support substrate, wherein a first contact layer of Ge or GaInAs, a Ge sub cell, a first tunnel junction, an InGaNAs sub cell, a second tunnel junction, a GaAs sub cell, a third tunnel junction, a GaInP sub cell and a second contact layer of InGaNAs or GaAs are arranged on the surface of the Si support substrate in sequence. The invention also provides a preparation method of the GaInP / GaAs / InGaNAs / Ge four-junction solar cell. The preparation method comprises the following steps: 1, a GaAs substrate is provided; 2, the second contact layer, the GaInP sub cell, the third tunnel junction, the GaAs sub cell, the second tunnel junction, the InGaNAs sub cell, the first tunnel junction, the Ge sub cell and the first contact layer are grown on the surface of the GaAs substrate in sequence; 3, the Si support substrate is provided; 4, the Si support substrate is bonded to the surface of the first contact layer; and 5, the GaAs substrate is stripped from the second contact layer, so that the GaAs substrate is removed.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to a GaInP / GaAs / InGaNAs / Ge four-junction solar cell and a preparation method thereof. Background technique [0002] In the field of solar cells, how to fully absorb the full spectrum of the sun, improve the generation efficiency of photogenerated carriers, and promote the separation of electrons and holes has always been the core key issue in improving the efficiency of solar cells. The current structural design of solar cells is basically based on the following two considerations: one is to give priority to lattice matching and put photocurrent matching in a secondary position. However, due to its determined bandgap energy, the lattice-matched cell structure limits the photocurrent matching of solar cells, making it impossible to realize full-spectrum absorption and utilization of sunlight. The GaInP / GaAs / Ge triple-junction solar cell is the most researched and technically mature system...

AI Technical Summary

Problems solved by technology

When GaInP / InGaAs / InGaNAs / Ge four-junction cells are grown on Ge substrates, reverse domains will be generated in the epitaxial layer when polar III-V semiconductor materials are grown on non-polar Ge substrates, which will affect the conversion efficiency of cells. ; In order to reduce the reverse domain density, a more complex buffer layer growth technique is required

At the same time, mass production of Ge-based triple-junction or quadruple-junction solar cells will cause a shortage of Ge materials.

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