Fully Conjugated Biscarboxylate Self‐Assembled Molecule Anchoring Enhances Conductive Oxide for Efficient Textured Perovskite/Silicon Tandem Solar Cells
Tingxia Yan, Enbo Zhou, Chi Li, Yanyi Zhong, Jiangbin Zhang, Kai Han, Zhenyu Jiang, Rui Lin, Peng Gao, Xinhua Ouyang
Abstract
Abstract The solution‐processible perovskite materials, utilizing the existing silicon infrastructure for perovskite/silicon tandem solar cells (P/S‐TSCs), have attracted significant interest due to their low‐cost and high efficiency. Hole‐selective layers (HSLs) are essential for charge extraction and transport in P/S‐TSCs. However, conventional HSLs often encounter issues such as poor conductivity, energy level mismatch, and incomplete coverage on textured surfaces. In this regard, a novel fully conjugated biscarboxylate‐anchored self‐assembled molecule with limited acidity, 5‐(9H‐dibenzo[a,c]carbazol‐9‐yl)‐isophthalic acid (IPAPhCz), is developed to enhance interaction with the conductive oxide of ITO (Indium tin oxide), which forms a uniform and conformal coverage that significantly improves the crystalline quality of the top perovskite. Additionally, IPAPhCz features a large tilted dipole moment with optimized energy alignment for hole extraction. The resulting 1.68 eV single‐junction PSC achieved a champion power conversion efficiency (PCE) of 22.78%, an increase of ≈10.37% over devices using 4PACz (PCE = 20.64%). Furthermore, textured P/S‐TSCs based on IPAPhCz reached a champion PCE of 31.80% (≈1 cm 2 ), reflecting a ≈9.58% enhancement compared to that on 4PACz (PCE = 29.02%). Both devices incorporating IPAPhCz demonstrated improved stability. The findings present a significant methodology for the design of high‐performance HSL materials for textured P/S‐TSCs.