The present invention embodies a solid state thermionic energy converter and is directed to a method and apparatus for conversion of thermal energy to electrical energy, and electrical energy to refrigeration. The present invention maintains a thermal separation between an emitter and a collector through a fractional surface contact of decreasing cross-sectional area towards the point of contact. The fractional surface contacts may be associated with the emitter, a barrier, or the collector. Maintaining a thermal separation between the emitter and the collector provides for ballistic electron transport through the barrier and reduces the transport of electrons through thermal conductivity. Hence, the efficiency is increased through the collection of ballistic electrons and the reduction of thermal conductivity electrons which cannot be collected. The inventive principle works for hole conductivity, as well as for electrons. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.