Flexible, Self-Powering, Dual-Functional Organic Sensory Device for Smart Indoor Environments

This research advances the field of flexible electronics by introducing a groundbreaking flexible, monolithic dual-functional sensory device, leveraging a multi-component organic photoactive structure to simultaneously achieve effective energy harvesting and high-precision sensing capabilities. The core innovation lies in the seamless integration of dual organic photovoltaic (OPV) and photodetector (OPD) functionalities within a single flexible device, marking a pioneering achievement in the realization of true image sensing with substantial energy efficiency.<br/>Addressing the significant challenges of operational efficiency and practicality, which have hindered the commercial viability of flexible indoor OPVs and OPDs for Internet of Things (IoT) applications, this study presents a device design that not only surpasses the current barriers of device efficiency but also offers a promising solution for sustainable indoor electronic devices. By meticulously optimizing the photoactive layer, this research has achieved a notable breakthrough in power conversion efficiency (PCE), reporting over 32% for rigid and 30% for flexible OPVs under standard indoor illumination conditions. This efficiency is underpinned by a sophisticated analysis of charge-carrier dynamics that ensures efficient molecular packing and an unprecedented free-charge generation yield.<br/>The practical application of this research is further demonstrated through the development of a self-powering single-pixel image sensor, which operates effectively in commercial indoor settings without external bias, showcasing exceptional photodetector performance with a linear dynamic range exceeding 130 dB in photovoltaic mode. The study's comprehensive approach extends to the exploration of the chemical and optical properties of the organic photoactive layer, facilitating the high performance of the OPD. Devices fabricated under this structure exhibited broad responsivity peaks in the red and near-infrared (NIR) wavelength regions, signifying the versatility and broad applicability of the sensory device in various lighting conditions. The detectivity metrics further validate the device's ability to discern weak signals, highlighting its potential for advanced sensing applications.<br/>Furthermore, the device's exemplary stability, maintaining a PCE of up to 90% even after 1800 hours without encapsulation under dim indoor lighting, points towards its reliability and longevity in practical applications. The combination of organic materials used in the photoactive layer not only enhances the device's efficiency but also significantly improves its flexibility. This flexibility allows for integration into various form factors and substrates, making it suitable for a wide range of applications in smart indoor environments. The flexible nature of the device enhances its mechanical robustness and enables innovative designs for IoT devices that can be seamlessly integrated into everyday objects. This durability, coupled with the device's high efficiency and dual-functionality, renders it a compelling candidate for future flexible indoor IoT devices and smart indoor environments.<br/>In sum, this research not only sets a new benchmark for the performance of flexible, monolithic sensory devices but also offers a strategic pathway for the development of sustainable indoor electronics. The novel monolithic dual-functional sensory device, with its efficient energy harvesting and precise sensing capabilities, stands as a significant contribution to the field, guiding future research towards exploring the full potential of organic-based optoelectronic technologies for indoor applications.