Multilayer Ohmic Contacts on CdS

Abstract
A multilayer technique for evaporation of Ohmic contacts onto CdS is described. The electrical properties of these contacts do not change markedly after vacuum heat treatment up to 350°C. This technique consists of a sequential evaporation of a preparative layer, an active metal and possibly a covering metal. The Ti (preparative)‐Al (active)‐Pt (cover) sequence has been found most successful. All the more than forty evaporations investigated on CdS single crystals, or on evaporated recrystallized layers, showed Ohmic characteristics between 2 mV and 200 V and showed only generation‐recombination noise above (at most) 300 Hz.