First, I hope this is the correct section of the forum to ask this question, otherwise I ask that this thread be moved.

I have read several studies on thermionic converter to convert heat directly into electricity because I find both the working principle and the purpose very interesting and useful. I am not here to go into too many technical details, but simply to ask what is the current state of the art of such a converter ... specifically whether we can achieve high efficiencies (I had read efficiencies of 30% for temperatures of 1000 °C, but the paper is from years ago, I think it's very low efficency ... isn't it?), whether they are used, whether it is a technology that is still being studied and especially what would be the main problems/challenges in the implementation of such a converter

If you want to refer me to the link of recent studies, I would be very grateful.

Thanks.

 

Thermionic conversion is still used, but not mainstream, because for most applications it does not compensate for the cost. The main exception is some heating systems that use the heat transfer to operate the controls. But I am not familiar with them, only aware of them.