Promises and challenges of indoor photovoltaics

Abstract

Indoor photovoltaics (IPVs) harvest ambient light to produce electricity, and can cleanly power the rapidly growing number of Internet of Things (IoT) sensors. The surge in IPV development, with new proposed materials, devices and products creates the need to critically evaluate how IPV devices have advanced, and their future prospects. In this Review, we analyze the status, challenges, and opportunities of established and emerging IPV technologies, including metal-halide perovskite, organic, dye-sensitized solar cell, and perovskite-inspired materials. Many emerging low-toxicity materials could reach IPV efficiencies of up to 50%, but carrier localization and defect trapping hinder their performance. Wide adoption of standardized performance assessment methods is essential, and further harmonization is needed for stress tests, qualification standards, and energy rating assessments. For seamless IPV integration in IoT devices, series-connected cell modules and appropriate power management hardware are crucial to maximize energy extraction. IPV device stability, technology upscaling, and cost-effective integration in IoT sensors must be further developed, but balanced with sustainability across the entire value chain.