Fig. 8

Physical mechanisms of TPL excitation and emission. a A complete TPL process consists of three steps: namely excitation step ①, relaxation step ② and emission step ③. │g > , │e1 > , │e2 > represent the ground stage, the excited state and the emission state, respectively. Reprinted with permission from The Journal of Physical Chemistry C 2016, 120, 17,699–17,710. Copyright 2016 American Chemical Society. b Two physical mechanisms to describe the excitation process of TPL are clarified by using autocorrelation experiments. Reprinted with permission from The Journal of Physical Chemistry Letters 2013, 4, 1634–1638. Copyright 2013 American Chemical Society. c Two sequential one-photon absorption (1PA) processed occurs near the symmetry points of X and L of the first Brillouin zone of gold. Reprinted with permission from The Journal of Physical Chemistry B 2005, 109, 13,214–13,220. Copyright 2005 American Chemical Society