Search

Quantum efficiency (QE) measurements of 150 nm nitrogen-incorporated ultrananocrystalline diamond films terminated with hydrogen, (N)UNCD:H, were carried out in the range between 250 and 440 nm. (N)UNCD:H demonstrated a QE as high as ~0.1 % at 254 nm. Additionally, (N)UNCD:H was sensitive in visible light (405 to 440 nm) with a QE of ~5×10-6 % at 405 nm, which is comparable with QE range of polycrystalline copper photocathodes operated at 250-270 nm (with no MV/m gradients on the surface). Note, the (N)UNCD:H samples were transported ex situ in air. Achieved high QEs in near UV and visible ranges are thanks to introduction of electron states in the band gap close to the conduction band minimum via nitrogen incorporation and negative electron affinity introduced by hydrogen states on the (N)UNCD surface. [ABSTRACT FROM AUTHOR]

An n-type doping significantly increases the number of active, Fe atoms substituting In (FeIn) in Fe-implanted InP. A previous theoretical study has shown that donor-acceptor pairs have direct stabilizing effects on FeIn related to charge rearrangements strongly localized at the Fe site and involving d orbitals. Here, we extend that study to Fe and Mn acceptors in InP and GaAs. Present results show that the theoretical model proposed for FeIn in InP generally holds for Fe and Mn acceptors in III-V semiconductors. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]