This is true also of gallium, tellurium and selenium, since all of them are past their production peak, which forewarns of imminent potential production shortages and escalating prices.
It has an inherent competitive advantage due to its use of Cadmium Tellurium (CdTe) in its panels instead of crystalline silicon (polysilicon) used by almost all its competitors.
That is about 50 times the abundance of tellurium which we looked at here and that therefore means that we have some 6 billion tonnes of indium to play with.
These are compounds of oxygen, sulphur, selenium and tellurium that are thought to be particularly suitable for thermoelectric applications because their structure allows electric currents to flow while blocking thermal currents.