In {HEAD ~ this case}, the first, second and third semiconductor layers are formed of {TAIL ~ a non single crystal semiconductor} doped with a dangling bond neutralizer 
In { HEAD ~ this case } , the first , second and third semiconductor layers are formed of { TAIL ~ a non single crystal semiconductor } doped with a dangling bond neutralizer
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH