Novel photocathodes using vacuum microelectronics technology

摘要

A new photocathode called a "photosensitive field emitter" has been proposed, and a prototype was fabricated. This new photocathode was realized using a gated Si field emitter tip and an hydrogenated amorphous Si (a-Si:H) p-i-n photodiode. The emission current from the photocathode is proportional to the illumination intensity, and detectable maximum of the illumination intensity was about 4000 μW/cm~(2). The quantum efficiency was about 0.7. Its dynamic range was about 200 times wider than that of the field emitter type photocathode using non-gated field emitter. Moreover, the dark current was suppressed less than 0.1 nA.