Investigation of GaAlAs photocathode with nanostructures sensitive to narrow band 532 nm wavelength

The underwater photoelectric detection equipment mainly uses 532 nm laser as the light source, and GaAlAs with Al component of 0.63 can obtain the cutoff wavelength near 532 nm, which is an excellent photocathode material to meet the requirement of narrow band spectral response of 532 nm laser. Furthermore, the light absorptance of the cathode can be improved effectively by the quadrangular prism or cylinder nanostructured arrays prepared on the reflection-mode Ga0.37Al0.63As cathode surface, and the maximum light absorptance can reach 96.2% at 532 nm, when the cylinder nanostructured array with a height of 900 nm and a base width of 100 nm. Nevertheless, the Ga0.37Al0.63As cathode with the quadrangular prism nanostructured array is less influenced by the incident angle of light.