Solar-blind deep-ultraviolet photodetectors based on an LaAlO_3 single crystal

Solar-blind deep-ultraviolet (DUV) photoconductive detectors based on an LaAlO(3) (LAO) single crystal with interdigitated electrodes are reported. The LAO detectors show a high sensitivity to DUV light with wavelengths less than 210 nm, and the DUV/UV (200 versus 290 nm) contrast ratio is more than 2 orders of magnitude. The photocurrent responsivity of LAO detector reaches 71.8 mA/W at 200 nm at 10 V bias, and the corresponding quantum efficiency eta is 44.6%. The noise current under sunlight at midday outdoors is only 77 pA. The experimental results indicate that the LAO detectors have attractive potential applications in DUV detection.