In this case, an exceptionally high photon flux of up to 442.2 µM s -1 (145.0 W L -1 radiant power density) was recorded in the 50 mL scale, which is an additional 52 % increase over the previous iteration. It should be noted that this power input is sufficient to heat up the solvent to boiling conditions within a short timeframe and thus, external cooling is absolutely mandatory. Individual emitters in this case reached 392.1 nM s -1 photon flux (128.6 mW radiant flux) which corresponds to 17.9 % of their rated output. While this still suggests significant untapped potential, it must be considered that powering LEDs with alternating current leads to light output only during the positive half-wave and then only once the minimum onset voltage has been reached. Therefore, realizing the full potential of the LEDs would require an internal rectifier to deliver a near-constant voltage to the emitter.