Patent ID: 8309838

Claim:
A semiconductor structure, comprising a first region, the first region having a first length and comprising a first semiconductor material doped with a first dopant to achieve a first carrier concentration; a second region, the second region disposed adjacent to the first region so as to define a first interface, the second region having a second length which is longer than the first length and comprising a second semiconductor material doped with a second dopant to achieve a second carrier concentration, wherein the first carrier concentration in the first region is between 5.4 and 22.4 times smaller than the second carrier concentration in the second region and wherein both the first and second regions are n-type regions or both the first and second regions are p-type regions; and wherein the first material, second material, first carrier concentration, second carrier concentration, first length, second length, first dopant, and second dopant are selected such that a forward electrical potential step is created at the first interface, the forward potential step having a barrier height dependent at least in part on an average temperature (T) of the semiconductor structure, wherein the forward potential step is defined such that a conduction band edge in the first region, at the first interface, is higher than a conduction band edge in the second region.