Solid and vapour phase UV photocathodes for gaseous detectors

We measured the relative quantum efficiency of four organic materials: tetrathiafulvalene and bis(cyclopentadienyl)magnesium in the solid phase and t-butylferrocene and n-butylferrocene in the vapour phase. The measurements were performed in the wavelength range of 150–220 nm. We also present a new quantum efficiency measurement of ethylferrocene. The three ferrocene derivatives exhibit relatively high quantum efficiency.