Method for tuning work function using surface photo voltage and producing ultra-low-work-function surfaces, and devices operational therewith

A method for tuning a work function in a thermionic emission device, comprising:

• illuminating an N type semiconductor material of a first member of a thermionic emission device, wherein a work function of the N type semiconductor material is lowered by the illuminating;
• collecting, on one of the first member or a second member of the thermionic emission device, electrons emitted from one of the first member or the second member;
• and
• applying a bias voltage between the first member and the second member, wherein the second member is biased to a positive voltage with respect to the first member, wherein the first member acts as an emitter of electrons, wherein the second member acts as a collector of the electrons, and wherein the thermionic emission device acts as a refrigeration mode device with the first member reducing a temperature as a result of the illuminating and the applying the bias voltage.

A method for tuning a work function in a thermionic emission device, comprising:

• illuminating an N type semiconductor material of a first member of a thermionic emission device, wherein a work function of the N type semiconductor material is lowered by the illuminating;
• collecting, on one of the first member or a second member of the thermionic emission device, electrons emitted from one of the first member or the second member;
• and
• illuminating a P type semiconductor material of the second member, wherein the second member acts as a cathode, wherein the first member acts as an anode, and wherein the thermionic emission device acts as a photon enhanced thermionic emission (PETE) energy converter.