Heavily doped semiconductor samples for Thermophotovoltaic Applications Thermophotovoltaic (TPV) generation of electricity offers fundamental adv relative to other direct energy conversion techniques (e.g., thermoelectric, The most important is the ability to recuperate the low energy waste T1000 0 C h > E g TRPL Up-conversion Photon Counting System PMT PPLN Reflective objective BS Sample 150 fs/100 MHz Nd:glass laser SF = PL + Las PL Las PC with LabView GPIB Monochromator Delay line I SF ~ I PL I PL I Las PL Las PL + Las NL crystal Excitation pulse Delayed laser pulse Las Luminescence PL delay Sum frequency radiation SF = PL + Las Photoluminescence Up-conversion Typical PL response of heavily doped semiconductor samples