Toward efficient energy conversion: a review on technological advances in thermophotovoltaics

This paper presents a systematic review of recent advances in thermophotovoltaic systems, exploring their potential to improve energy conversion efficiency and electrical stability. Thermophotovoltaic systems offer a distinct approach to energy utilization by converting thermal energy into electricity covering their detailed components, including the heat source, emitter, filter, thermophotovoltaic cell, and structural features. First, the characteristics and application prospects of different types of heat sources, such as combustion, solar energy, radioisotopes, near-field, waste heat, and thermal storage, are analyzed. Subsequently, the selection of emitter materials, the design of filters, and the type and optimization of thermophotovoltaic cells are investigated, with particular emphasis on the importance of spectral selectivity in improving system efficiency. Key challenges identified include emitter durability at temperatures above 1500°C, the persistent gap between cell-level (>40%) and system-level (<15%) efficiencies, and the lack of standardized performance evaluation protocols. Finally, the efficiency of thermophotovoltaic systems is evaluated, and future development trends are discussed. This review provides a comprehensive perspective on the technological development of thermophotovoltaic systems and identifies the key challenges in achieving industrialization and commercialization.