Properties of Cadmium Selenide Thin Films as a Function of Lateral Distance from Chromium Contacts

The electrical, structural, and compositional properties of CdSe thin films were examined as a function of lateral distance from Cr contacts. The local threshold voltage of CdSe transistor channels was large and negative near the contacts and eventually approached a maximum positive value. This result is consistent with heavy n‐type doping of the CdSe caused by lateral diffusion of chromium contact metal. Energy‐dispersive x‐ray analysis (EDAX) showed that chromium had diffused into the CdSe film up to a distance of 20 μm from the contacts. For films annealed with a maximum temperature of 370°C, the grain size was uniform across the channel. Samples annealed at 400°C for 4 h had an enhanced grain size near the contacts.