the conduction layer, the transition layers, and the charge accumulation layer are respectively made of a Group III V compound semiconductor including at least one element selected from the group consisting of In and {TAIL ~ Ga} of {HEAD ~ the Group III element} and As of the Group V element; and 
the conduction layer , the transition layers , and the charge accumulation layer are respectively made of a Group III V compound semiconductor including at least one element selected from the group consisting of In and { TAIL ~ Ga } of { HEAD ~ the Group III element } and As of the Group V element ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH