A solid state energy generator and storage device, comprising two layers, in contact with each other, of dissimilar materials in terms of electron density and configuration, sandwiched between an anode and a cathode. One of the layers is a stabilized mixture of carbon and an ionic material (carbon matrix) and the other layer is a stabilized manganese oxide mixed with an ionic material (oxide matrix). The built-in potential of the device is determined mathematically by integrating the electrostatic forces across the barrier and will rise or fall in direct proportion to the device temperature (in Kelvin). In addition the device can be charged and thus function as a charge storage device, with the rated voltage varying according to the temperature of the device. When a load is attached across the terminals of the device a current flows.