", Ag, an alloy including Ni, an alloy including Ag, and an alloy including Ti, and,(iv) the metal for the electrode layer in contact with the second layer is specified as one of Al, Ti, an alloy including Al, and an alloy including Ti.Claim 1 of the auxiliary request II differs from claim 1 of the main request in that (i) it specifies that the i-type and the n-type layers are of AlxGa1-xN, x >= 0," . . . . .