The small ΔELE-CT will increase the radiative ability of the CT state by hybridizing the CT and LE, known as the intensity-borrowing mechanism . Crucially, the small ΔELE-CT enables the upconversion from the 1 CT to the highly emissive 1 LE. This opens an additional radiative relaxation pathway from the CT state through the highly emissive LE state. Because of the very small ΔELE-CT in the DAAPC/2-PPT system, thermal activation is not required for the upconversion from CT to 1 LE. This is reflected in the TL map, where distinct 1 LE emissions are observed even below 100 K and with almost no visible CT state emission.