Abstract: Traditional solid oxide fuel cells (SOFCs) require high operating temperatures, which are not conducive to the compatibility and long-term stability of their various components, hindering the commercial progress of SOFCs. Reducing the reaction temperature can lead to significant interfacial resistance and losses in reaction kinetics, resulting in a reduced output power. Recently, single-component fuel cell (SLFC) has been proposed as a new type of energy conversion device. Unlike the traditional three-component SOFCs, the SLFC is characterized by a homogeneous layer of semiconductor-ion heterostructure material with mixed ionic conductivity. The presence of p-n heterojunctions and built-in electric fields can achieve charge separation, enhancing the stability and durability of the fuel cell, allowing it to have good ionic conductivity and cell performance even at low temperatures, and offering broad prospects for development. This paper provides a brief overview of the research progress in the field of SLFCs in recent years, reviewing the working principle of heterojunctions and energy band alignment in SLFCs to isolate electrons, studying the effects of space charge regions and lattice strain on interfacial ionic conduction, summarizing the improvements made by researchers on semiconductor-ionic materials, and discussing the advantages and future development directions of SLFC.