Precisely creating large number of oxygen vacancies (defects) in already existing thermoelectric materials improves thermoelectric efficiency 91%

https://www.eurekalert.org/news-releases/1096100

"transverse thermoelectrics generate voltage drop perpendicular to heat flow direction... when material has more oxygen vacancies, entropy difference inside becomes larger, driving electric charges to flow more strongly along temperature gradient, making electricity generation more efficient... vacancies slightly distort material’s crystal structure, causing some straight-flowing charge flow to shift sideways increasing transverse thermoelectric efficiency... no complex/ expensive new materials... applies to many thermoelectric materials"