Abstract
Portable or miniaturized gadgets have seen rapid development in recent years, yet their power supply remains a major obstacle, often relying on external sources. Herein, we present a portable self-powered device for sensing the NO2 gas. This concept integrates a perovskite photovoltaic cell (8.84% conversion efficiency) for energy harvesting, a sodium-preintercalated delta-type MnO2-based supercapacitor (energy density of 0.76 mu Wh cm-2 at a power density of 0.025 mW cm-2) for energy storage, and a graphene nanoplatelet-based NO2 sensor (10.8% response at 10 ppm of NO2) as the energy consumption module, all on a single glass substrate in a miniaturized scale. Under illumination, the perovskite solar cell generates electricity, and the supercapacitor stores the energy and regulates the output voltage for powering the NO2 sensor. The high-level integration, achieved through rationally designed and modularized components, minimizes inactive spaces and eliminates cumbersome connections. This study introduces a modular and scalable platform for integrating energy harvesting, storage, and consumption on a single chip, essential for the next generation of ubiquitous electronic devices.