example 1 was carried out with the addition in that an amount of li to provide a li doped concentration of 10 16 10 17 cm 3 in the resultant hg x zn 1 x si layer was added to the hg bath in the form of solid li 1 v plots measured on structures prepared according to these examples are shown in fig3 9 the information regarding the formation of the hg x zn 1 x se layer and the metal contact is given in the heading under 34 graphics plot 34 thus in fig3 34 mbe 880 34 identifies the layer 34 hg 34 indicates that the layer was undoped i e without li 34 325c 4hr 34 indicates that the alloying was carried out at a temperature of 325y u00b0 c for a period of 4 hours and 34 sd 34 indicates the size of the contact area of the gold contact in the plot in fig3 this is indicated to be 2 u00d7 10 3 cm 2 in fig4 34 100c 1hr 34 indicates that the layer was heated at a temperature of 100 u00b0 c for a period of 1 hour after the alloying following removal from hg bath to form hg vacancies in fig5 34 mbe871 34 identifies the layer.