Solar-blind deep-ultraviolet photodetectors based on an LaAlO3 single crystal

Solar-blind deep-ultraviolet (DUV) photoconductive detectors based on an LaAlO3 (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. (C) 2009 Optical Society of America