The integrating sphere was calibrated using a radiometric source (HL-3P-CAL, Ocean Insight), which emits a known power at specific wavelengths. This calibration was used to convert arbitrary counts into absolute irradiance (μW/nm). Four measurements shown below were taken for each sample to calculate the UC quantum yield, which are modified from PLQY measurements developed by de Mello. 1. Exp A: There was no sample in the integrating sphere, and the emission collected from the sphere was cut off by a 425 nm short pass filter to prevent saturation of the detector.