The apparatus 5, wherein each photodiode comprises {HEAD ~ a P+ layer} doped into {TAIL ~ the bulk semiconductor material} 
doped into
The apparatus 5 , wherein each photodiode comprises { HEAD ~ a P+ layer } doped into { TAIL ~ the bulk semiconductor material }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL