High-Performance Narrow-Band Self-Powered Solar-Blind Ultraviolet Photodetector Enabled by the Hf0.5Zr0.5O2/(Sn0.1Ga0.9)2O3 Heterojunction

While ferroelectric-enhanced Ga2O3-based self-powered solar-blind ultraviolet photodetectors (SBUVPDs) can offer high-performance detection of 200–280 nm wavelength due to efficient carrier separation, their accuracy is often compromised by the narrow bandgap (<4 eV) of traditional ferroelectric materials, which makes them susceptible to interference from light signals beyond the SBUV region. To address this issue, we developed a narrow-band self-powered SBUVPD based on Hf0.5Zr0.5O2/(Sn0.1Ga0.9)2O3 heterojunction thin films. This device benefits from a strong ferroelectric depolarization field throughout the whole Hf0.5Zr0.5O2 thin film, and a type-II band alignment at the interfaces of Hf0.5Zr0.5O2 and (Sn0.1Ga0.9)2O3, yielding excellent photoresponse performances with a high responsivity of 25.10 mA/W, large detectivity of 4.63 × 1011 Jones, and fast rise/decay time of 201/325 ms at 0 V bias. Crucially, the ultrawide bandgap (5.45 eV) of Hf0.5Zr0.5O2 confines the cutoff wavelength to within 280 nm, ensuring high detection accuracy. The overall performances of this device outperform those of the most recently reported SBUVPDs utilizing Ga2O3 materials, demonstrating that integrating ultrawide-bandgap ferroelectric layers is an effective strategy for creating high-property, narrow-band SBUVPDs.