NOVELTY - Semiconductor structure comprises two regions having respective length, and two semiconductor materials doped at respective concentration with dopants. The materials, concentrations, lengths, dopants are selected so that a forward electrical potential step is created at an interface. The forward potential step has a barrier height dependent on an average temperature of the semiconductor structure.    USE - The semiconductor structure is used for thermoelectric applications such as for cooling, say semiconductor lasers and detectors, and for generating power (claimed).    ADVANTAGE - The inventive semiconductor structure has improved efficiency. The thermal-electric behavior near the sharp potential step can be exploited to build refrigeration, heat pump, and power generation devices with improved efficiency over existing thermoelectric devices.    DETAILED DESCRIPTION - Semiconductor structure comprises: a first region having a first length and a first semiconductor material doped at a first concentration with a first dopant; and a second region disposed adjacent to the first region to define an interface. The second region has a second length, which is longer than the first length. It has a second semiconductor material doped at a second concentration with a second dopant. The two materials, two concentrations, two lengths, two dopants are selected so that a forward electrical potential step is created at the interface. The forward potential step has a barrier height dependent on an average temperature (T) of the semiconductor structure.    INDEPENDENT CLAIMS are also included for:    (a) method for providing a first semiconductor structure for use in thermoelectric applications comprising providing two regions arranged adjacent to each other and selecting the first material, second material, first concentration, second concentration, first size, second size, first dopant, and/or second dopant so that a forward electrical potential step is created at the interface;    (b) method of changing the temperature of an object or area comprising providing a potential amplified nonequilibrium thermal electric device (PANTEC) having two sides, disposing the first side of the PANTEC adjacent to a first object and/or area whose temperature is to be changed, disposing the second side of the PANTEC adjacent to a second object and/or area constructed and arranged to receive heat and/or cold, applying a current so that electrons and/or holes leave the first side of the PANTEC if the first object or area is to be cooled, and applying a current so that electrons and/or holes flow towards the side of PANTEC where the first object or area is to be heated; and    (c) method of generating power comprising providing PANTEC, disposing the first side of the PANTEC adjacent to a heat source, and disposing the second side of the PANTEC so that it is in connection with the object or area capable of operating as a heat sink.