Aqueous Solution-Grown Crystalline Phosphorus Doped Indium Oxide for Thin-Film Transistors Applications

Solution-grown indium oxide (In₂O₃) based thin-film transistors (TFTs) hold good prospects for emerging advanced electronics due to their excellent mobility, prominent transparency, and possibility of low-cost and scalable manufacturing; however, pristine In₂O₃ TFTs suffer from poor switching characteristics due to intrinsic oxygen-vacancy-related defects and require external doping. According to Shanmugam’s theory, among potential dopants, phosphorus (P) has a large dopant–oxygen bonding strength (E_M-O) and high Lewis acid strength (L) that would suppress oxygen-vacancy related defects and mitigate dopant-induced carrier scattering; however, P-doped In₂O₃ (IPO) TFTs have not yet been demonstrated. Here, we report aqueous solution-grown crystalline IPO TFTs for the first time. It is suggested that the incorporation of P could effectively inhibit oxygen-vacancy-related defects while maintaining high mobility. This work experimentally demonstrates that dopant with high E_M-O and L is promising for emerging oxide TFTs.