While the shift toward surface-textured three-dimensional (3D) architectures in photovoltaics significantly enhances light trapping, it also poses considerable challenges to conventional transparent electrodes. Indium tin oxide (ITO) and fluorine doped tin oxide (FTO) suffer from poor sidewall coverage due to physical vapor deposition line-of-sight limitations, while AgNWs networks exhibit work function mismatch with silicon, inducing Schottky barriers. Carbon nanotubes (CNTs) offer favorable work function alignment yet lack sufficient lateral conductivity alone. We propose a CNTs/AgNWs/PVA three-dimensional composite electrode fabricated via sequential spin-coating onto patterned sapphire substrates followed by polyvinyl alcohol (PVA) encapsulation and peel-off. The outermost CNTs layer establishes near-ohmic contact with silicon, minimizing interfacial barriers, while the embedded AgNWs network provides high-conductivity lateral transport. The PVA matrix enables conformal replication of complex topographies. The composite electrode achieves a transmittance of 83.64% at 550 nm, with a thin layer resistance of 10 Ω/sq, and possesses excellent mechanical flexibility and environmental stability. At the same time, it also has excellent stability in light transmittance and effective suppression of UV transmission going to strong absorption by CNTs. In theory, compared to AgNWs/PVA electrodes, it demonstrates enhanced charge collection on textured silicon surfaces and improved long-term stability against UV-induced degradation. This structural-functional synergistic design offers a promising interface engineering strategy for high-efficiency three-dimensional photovoltaic devices.
Yang et al. (Thu,) studied this question.