Programming-voltage-induced interface charge redistribution for a Lu₂O₃/Nb:SrTiO₃ deep-ultraviolet photodetector:...

Reconfigurable optoelectronic logic gates (OELGs) operating at zero bias are highly desirable for advancing big-data computing. However, most existing strategies face a trade-off in which reconfigurable schemes typically require a continuous holding voltage (resulting in static power), whereas zero-bias approaches often rely on multiple-wavelength switching (complicating the system). Herein, we demonstrate reconfigurable logic operations at zero bias in a single Pt/Lu₂O₃/Nb:SrTiO₃ (NSTO) deep ultraviolet (DUV) photodetector (PD). This is achieved via a novel unipolar photocurrent-amplitude modulation strategy. Brief pulses of opposite-polarity programming voltages (V_pgm) reversibly tune the interfacial barrier height at the Lu₂O₃/NSTO heterojunction, thereby modulating the photoresponse amplitude. The device's initial responsivity (5 mA/W under 258 nm illumination and 0 V bias) can be enhanced to 24.3 mA/W (V_pgm = +5 V) or suppressed to 3.6 mA/W (V_pgm = -5 V). Coupled with optical power modulation, a single DUV light enables reconfigurable AND, OR, and XOR operations in the same device without any holding bias. The programmed high-responsivity state exhibits long-term retention (>15 days) and good reproducibility across six devices. This work provides a design strategy for developing single-device, multifunctional OELGs with low static power consumption, holding promise for applications in adaptive sensing and neuromorphic computing systems.