THE ROLE OF SEMICONDUCTING ELECTRIDES IN MECHANICAL ENERGY CONVERSION AND PIEZOELECTRIC APPLICATIONS: A SYSTEMATIC LITERATURE REVIEW

Abstract

Electrides have emerged as promising materials for next-generation energy harvesting and storage technologies, offering exceptional electronic properties, including high electron mobility, low work function, and superior charge transport characteristics. This systematic review, based on an extensive analysis of 112 peer-reviewed studies encompassing over 3,500 citations, examines the integration of electrides into piezoelectric nanogenerators (PENGs), triboelectric nanogenerators (TENGs), hybrid energy harvesting systems, photovoltaic applications, thermoelectric devices, and commercial energy storage solutions. The findings indicate that electride-enhanced nanogenerators exhibit 2.5 to 3 times higher energy conversion efficiency compared to conventional materials, with hybrid PENG-TENG systems demonstrating a 30% increase in voltage output and a 25% reduction in charge dissipation. In photovoltaic and thermoelectric applications, electride-based electron transport layers (ETLs) improve solar power conversion efficiency by 15–20%, while electride-doped thermoelectric materials enhance thermal-to-electric conversion by 20–35%, making them viable candidates for waste heat recovery and renewable energy integration. Despite these advantages,
the review identifies key challenges in scalability, material degradation due to oxygen and moisture exposure, and the need for cost-effective fabrication techniques. Recent advances in thin-film deposition methods, such as chemical vapor deposition (CVD) and atomic layer deposition (ALD), along with surface passivation techniques, have shown potential in addressing these limitations, paving the way for commercial adoption of electride-based energy devices. Additionally, over 60% of reviewed studies highlight the successful implementation of electrides in self powered IoT systems, wearable electronics, and hybrid energy storage solutions, demonstrating their real-world applicability in smart infrastructure, biomedical implants, and wireless sensor networks.