In a preferred embodiment, {TAIL ~ the p type zinc oxide film} contains {HEAD ~ arsenic} and is grown on a gallium arsenide substrate 
In a preferred embodiment , { TAIL ~ the p type zinc oxide film } contains { HEAD ~ arsenic } and is grown on a gallium arsenide substrate
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH