Vacuum deposition of CsPbI₃ layers on textured Si for Perovskite/Si tandem solar cells

Abstract

We attempt the conformal deposition of CsPbI3 layers on pyramidal-shaped textured crystalline Si (c-Si) surfaces, aiming at application to Perovskite/Si tandem solar cells. CsPbI3 layers are deposited through vacuum evaporation on textured c-Si surfaces with various pyramid sizes. Conformal CsPbI3 layers are formed on the textured c-Si, which is, in principle, difficult to be realized by conventional solution processes. We also confirmed a reduction in the optical reflectance of CsPbI3/Si structures by ∼10% (absolute) by using textured c-Si compared to the case of flat Si. A co-evaporation method can prevent the aggregation of CsI particles, which are seen when the films are formed by sequential evaporation. These results indicate the feasibility of Perovskite/c-Si tandem cells with textured c-Si, leading to low optical reflectivity and a high photocurrent.

From Groundwork to Efficient Solar Cells: On the Importance of the Substrate Material in Co‐Evaporated Perovskite Solar Cells

“…[42,45,46] In addition, vacuum processing has been demonstrated to be capable to overcome the problem of inhomogeneous deposition on top of the textured and rough surfaces. [38,[62][63][64] In that regard, Sahli et al realized a fully texture two-terminal perovskite/silicon tandem solar cell with a PCE exceeding 25% by first evaporating PbI 2 on top of the textured silicon surface, followed by a solution-based conversion into perovskite. [58] Despite the fact that promising results were obtained from vacuum-deposited perovskite absorbers and all-evaporated perovskite solar cells, thorough investigations into the co-evaporation process itself are rare.…”

All‐Inorganic Cesium‐Based Hybrid Perovskites for Efficient and Stable Solar Cells and Modules

“…[100] However, experimental works on tandem devices comprising all-inorganic perovskites are quite scarce. [100][101][102] This is mainly due to the intrinsic instability of the CsPbI 3 active layer, [100,103] which still limits its successful implementation in tandem configuration. However, the methods aiming to increase the Goldsmith tolerance factor to improve the stability of the CsPbI 3 photoactive phase discussed in the review can be easily translated from single junction device optimization to tandem structures, encouraging timely improvements of CsPbI 3 tandem devices.…”

Metal halide perovskite solar cells by modified chemical vapor deposition

“…Assuming a 100% internal quantum efficiency, this reduction of reflectance equals around 2 mA cm −2 short-circuit density. 93 Further efforts are needed for CVD-deposited conformal pyramidal textured perovskite/Si tandem cells.…”