Why Li's solar cell concept cannot work

The so-called Li cell or junction near local defect (JNLD) layer device founded upon a discontinuous local defected layer (LDL) inserted in the emitter near the p-n junction raised many hopes since its description in May 1992. The next two years were delusive because of many negative results. Why does it not work when the concept of Si modification to enlarge its optical absorption has been known in solar community from the 1970s and the built-in electric field improvement postulated since the 1960s? The main problems are to know which potentially applicable improvements are actually important and then to put the different separately proven phenomena together. It is easier to understand the contradictions of Li's concept by comparing the cell with a well-working structure. Some of the authors' concepts and physical modeling published recently allow this analysis although the two approaches are founded on different principles concerning especially the inserted layer fine structure, the built-in electric field distribution, and the electronic transport in the cell emitter.