부산대학교 도서관

It has been found that germanium wafers containing a p-type impurity and lithium, a high atomic mobility n-type impurity, may be used to construct junction devices, called flexodes, whose I–Vcharacteristics may be reversibly transformed between resistive and rectifying states. These transformations result from the application of electric fields at intrinsic temperatures (≳ 100°C). They are due to field-enhanced diffusion of Li+ions. Reverse bias is thought to cause electric-field-controlled precipitation of excess lithium in the region of the p—njunction. Such precipitation can degrade the rectification by causing breakdown and shorting of the junction. The precipitates may be removed from the junction region and the rectification may be restored by the application of forward bias. Methods of making flexodes and of obtaining the junction transformations are described, and a qualitative model for the growth of precipitates in the applied electric field is discussed. Several proposed practical applications of flexodes are also included.