Perovskite solar cells (PSCs) have emerged as a transformative photovoltaic technology, achieving power conversion efficiencies (PCEs) rivaling those of traditional silicon-based devices. However, widespread commercialization is hindered by the use of costly and degradation-inducing metal electrodes (such as gold), which complicate large-scale fabrication and compromise long-term device stability. Carbon-based electrodes offer a compelling alternative due to their inherent chemical stability, low cost, and compatibility with scalable processes. Among various approaches, laminable carbon electrodes (in which pre-formed carbon films are applied to perovskite half-cells) have shown significant promise by eliminating solvent incompatibility with underlying charge transport layers.

Despite these advantages, a critical challenge remains: the performance gap between laminated carbon electrodes and metal-based counterparts, particularly due to higher series resistance and suboptimal interfacial contact. Moreover, the universal applicability of laminated carbon electrodes across both conventional (n-i-p) and inverted (p-i-n) architectures has not been thoroughly validated.

In this study, we present a unified lamination strategy that enables high-performance PSCs in both n-i-p and p-i-n configurations by integrating solvent treatments and tailored interlayers specific to each architecture. We demonstrate that post-lamination treatment of carbon films with appropriate solvents reduces the porosity of the electrode, thereby improving both contact and sheet resistance. This engineering step significantly mitigates the performance loss typically associated with laminated carbon electrodes. As a result, we achieve PCEs exceeding 21% in n-i-p devices and 19% in p-i-n devices. These values correspond to over 95% of the efficiency achieved by reference metal-based devices, while also exhibiting superior stability and negligible hysteresis.

To further address contact limitations, we investigated the effect of solvent exchange on freestanding carbon films using the transfer length method (TLM), revealing significant reductions in both sheet and contact resistance. Additionally, implementing a sandwich electrode design incorporating graphite paper and aluminum foil improved lateral conductivity and mechanical robustness without compromising the perovskite layer. These advances demonstrate the scalability potential of laminated carbon electrodes for large-area perovskite solar modules.