Self-encapsulated wearable perovskite photovoltaics via lamination process and its biomedical application.

Flexible perovskite solar cells (PSCs) are highly promising photovoltaic technologies due to the prospect of integration with wearable devices. However, conventional encapsulation strategies for flexible devices often cause secondary damage to the perovskite crystals, which affects device performance. Here, we present self-encapsulated flexible PSCs realized by lamination technology. The conversion of perovskite crystals is achieved by the diffusion of lead iodide and ammonium halide under the effect of temperature and pressure. In addition, the hydrogen bonding of the introduced polyacrylamide enhances the connections of the integral device while improving the crystal quality. The self-encapsulated flexible PSCs achieve an outstanding photovoltaic conversion efficiency of 22.33%, and comprehensive stability tests are conducted based on wearable device application scenarios to verify the feasibility. Finally, 25 cm wearable perovskite modules are successfully applied into the neuro-assisted wearable devices.