|A radiation detector comprises a silicon body in which are defined
vertical pores filled with a converter material and situated within
silicon depletion regions. One or more charge-collection electrodes are
arranged to collect current generated when secondary particles enter the
silicon body through walls of the pores. The pores are disposed in
low-density clusters, have a majority pore thickness of 5 .mu.m or less,
and have a majority aspect ratio, defined as the ratio of pore depth to
pore thickness, of at least 10.