Low-Temperature Solution-Processed Lu2O3 Films for Deep-UV Photovoltaic Detectors With High Sensitivity

In this work, a low-temperature solution process is proposed to synthesize Lu ₂ O ₃ films with few surface defects for the purpose of fabricating high-performance deep-ultraviolet (DUV) detectors. Based on the solution-processed Lu ₂ O ₃ film treated at 250 °C, a high-sensitivity Lu ₂ O ₃ /GaN DUV photovoltaic detector is fabricated, which has exhibited excellent performance in many aspects. At 0 V bias voltage, it displays a peak photoresponsivity of 41.6 mA/W at 258 nm and a DUV to visible rejection ratio ( $\text{R}_{258\,\text{nm}} / \text{R}_{405\,\text{nm}}$ ) higher than two orders of magnitude. What’s more, compared with devices based on high-temperature (500 °C) solution-processed (H-T) Lu ₂ O ₃ film, the device prepared in this way shows a greater photoresponsivity and a response speed faster than an order of magnitude, which can be attributed to the fewer surface defects aroused during the low-temperature solution process. The great characteristics achieved suggest the Lu ₂ O ₃ film treated by the method of low-temperature solution process can be applied to fabricating high-performance DUV detectors.