Stacked photovoltaic device

Abstract

Provided is a stacked photovoltaic device characterized in that: a first i-type semiconductor layer comprises amorphous silicon hydride, and second and subsequent i-type semiconductor layers comprise amorphous silicon hydride or microcrystalline silicon, the i-type semiconductor layers being stacked in order from a light incidence side; and when an open circuit voltage is assigned Voc in the case where a pin photoelectric single element is manufactured using a pin element having the i-type semiconductor layer made of microcrystalline silicon of pin elements having the second and subsequent i-type semiconductor layers, respectively, and a layer thickness of the i-type semiconductor layer concerned is assigned t, a short-circuit photoelectric current density of the stacked photovoltaic device is controlled by the pin element including the i-type semiconductor layer having the largest value of Voc / t.

Description

technical field [0001] The present invention relates to photoelectric elements such as solar cells, sensors, and imaging elements, and more particularly to a multilayer photoelectric element in which a plurality of pin junctions are laminated. Background technique [0002] So far, there have been many disclosures on the technology of stacked photovoltaic elements in which a plurality of pin elements are connected in series for the purpose of increasing the efficiency of amorphous silicon solar cells and reducing photodegradation. By stacking into one, sunlight can be divided into multiple wavelength-sensitive regions and absorbed, so that photogenerated carriers can be used more efficiently, and at the same time, photogenerated carriers generated by each element can be reduced to reduce photodegradation . [0003] For example, a-SiC / a-Si / a-SiGe, a-Si / a-SiGe / a-SiGe, a-SiC / a-SiGe / a - Elements such as SiGe (see Japanese Patent Application Laid-Open No. 5-102505), experiments ...

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Problems solved by technology

[0008] However, since it is considered that microcrystalline silicon has less or almost no characteristic deterioration due to light irradiation compared with amorphous silicon, in a stacked photovoltaic element in which a plurality of i-type semiconductor layers are formed of microcrystalline silicon, for The question of which laminated structure is most suitable for the characteristics of photovoltaic power generation has not been disclosed so far to provide a clear answer to this question

[0009] However, in fact, even in microcrystalline silicon, the film quality and photodegradation characteristics are greatly different depending on the formation conditions and film thickness. Therefore, it is necessary to fully consider the photodegradation characteristics of microcrystalline silicon when designing multilayer photovoltaic devices.

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