Thermophotovoltaic and photovoltaic conversion at high-flux densities

We first discuss the similarities between generation of electricity using t hermophotovoltaic (TPV) and high-optical-concentration solar photovoltaic ( PV) devices, Following this, we consider power losses due to above- and bel ow-bandgap photons, and we estimate the ideal bandgap by minimizing the sum of these, for a 6000 K black-body spectrum. The ideal bandgap, based on th is approach, is less than that previously predicted, which could have a sig nificant influence on the performance of devices and systems. To reduce the losses, me show that the low-energy photons may be removed from both types of cells and consider the specific case of a back surface reflector. This approach to the management of waste heat mag offer a useful additional tool with which to facilitate the design of high-photon-flux solar cells. in th e case of the high-energy photons and the associated problem of thermalizat ion of hot electrons, however, the heat must be removed by other means, and we consider the applicability of microchannel cooling systems. These appea r to have the potential to handle thermal loads at least several times thos e generated by 1000 times concentrators, or by black-body TPV radiators at a temperature of far greater than 1500 K. We go on to consider the manageme nt of the very high currents generated in both concentrator TPV and PV syst ems and discuss the concept of the monolithically integrated minimodule.