Crystalline silicon heterojunction solar cell

Abstract

A crystalline silicon heterojunction solar cell, the structure of which starts from the light-facing surface: front electrode, TiO x Layer, crystalline silicon absorption layer, intrinsic amorphous silicon passivation layer, p-type amorphous silicon heavily doped layer, back electrode. Use n-type doped TiO on the light-facing surface x Form a heterojunction with crystalline silicon, while the backside uses a conventional amorphous silicon / crystalline silicon heterojunction structure. Due to TiO x The optical band gap is wide, and almost all the sunlight incident from the light-facing surface can enter the interior of the crystalline silicon, thereby avoiding the loss of photo-generated current due to the absorption of the window layer. In addition, TiO x It can well passivate the surface of the silicon wafer and form a good heterojunction with silicon, which helps to increase the open circuit voltage of the heterojunction cell. Therefore, the crystalline silicon heterojunction solar cell proposed by the present invention can simultaneously realize high open circuit voltage and short circuit current, and improve the photoelectric conversion efficiency of the crystalline silicon heterojunction solar cell.

Description

technical field [0001] The invention belongs to the field of solar cells and the field of semiconductor devices, and relates to the structural design of silicon solar cells. Background technique [0002] Photovoltaic power generation is an important clean energy. Under the background of global environmental pollution and energy shortage, photovoltaic power generation has developed rapidly in recent decades. However, the current cost of photovoltaic power generation is still higher than the cost of traditional power generation. To promote the popularization of photovoltaic power generation, it is necessary to reduce the preparation cost of solar cells as the main body of photovoltaic power generation and improve their photoelectric conversion efficiency. [0003] Since silicon is abundant in the earth's crust and its purification technology is relatively mature, and its optical band gap matches the solar spectrum, silicon is an ideal material for solar cell preparation. Most...

AI Technical Summary

Problems solved by technology

Although HIT solar cells can achieve a large open circuit voltage (maximum 750 mV), due to the narrow band gap and large light absorption coefficient of the amorphous silicon material used as a passivation layer and emitter, a part of sunlight is absorbed by internal defects. Much amorphous silicon absorbs and fails to convert into photogenerated current

Although the absorption of sunlight by the amorphous silicon layer can be reduced by doping the amorphous silicon with oxygen, but the oxygen doping also increases the series resistance of the battery, so the photoelectric conversion efficiency of the battery has not been significantly improved.

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