Red Fluorescence Enhancement and Optical Communication Performance of CuI Crystals Grown in HI Solution

The photoluminescence (PL) of cuprous iodide (CuI) has drawn significant attention in the scientific community. In order to investigate the growth methods and environmental conditions on the fluorescence, we first prepared CuI via immersion of copper in hydroiodic acid. This method is beneficial for the growth of large grains (> 20 mu m) with intensive red fluorescence emission at 708 nm. The fluorescence has a high quantum yield (34 %), and superior stability. Then we studied the fluorescence behaviors in water. We observed fluorescence quenching, which is due to the energy transfer. Additionally, we studied the effect of temperature on the fluorescence. We found that the fluorescence intensity increased initially then decreased as the temperature increased. The underlying mechanism was analyzed in terms of fluorescence quencher (water) removal and thermal quenching. By controlling heating, we successfully obtained intensive and pure red fluorescence. Finally, we explored the potential application of the red fluorescent of CuI in optical communication. The results demonstrate bit error rates within permissible range of forward error correction, highlighting the superior performance of CuI in optical communication systems.