[20p-PB4-1~57] 12.5 Organic solar cells

[20p-PB4-29] Surface treatment of transparent conductive layer using highly crystalline fine TiO₂ particles for low-temperature perovskite solar cells

〇Tsuyoshi Abe¹, Masashi Ikegami¹, Tsutomu Miyasaka¹ (1.Toin Univ of Yokohama)

Keywords:perovskite solar cell, low-temperature coating

Perovskite solar cells are well-known as highly efficient solar cells exceeding 20% in energy conversion efficiency, even when they are fabricated using simple coating processes. However, such high efficiencies have been achieved only in small-sized cells with an active area lesser than 1 cm². However, for practical applications, development of large-area coating methods will be necessary. A spin-coating process is usually used in the fabrication of small-area solar cells. On the other hand, patterned coating processes are needed to fabricate large-area modules. In the normal structure of perovskite solar cells, at least four layers are needed: an n-type semiconductor layer, a perovskite layer, a hole transport layer, and a metal electrode on a transparent conductive glass. In this study, we focus on the n-type semiconductor layer made by TiO2 fine particles with a size of 7 nm. Particles with a size of 7 nm have a very large area[A1] of 300 m²/g, and such a large area produces aggregation characteristics. Such aggregation will cause particle necking, even at room temperature, resulting in a very dense layer which is called a compact layer. In this presentation, we discuss the relationship between compact layer formation conditions and the energy conversion efficiency of perovskite solar cells.