Luminescence Saturation via Mn2+-Exciton Cross Relaxation in Colloidal Doped Semiconductor Nanocrystals

作者：Bradshaw Liam R; Hauser Andreas; McLaurin Emily J; Gamelin Daniel R^*

来源：Journal of Physical Chemistry C, 2012, 116(16): 9300-9310.

DOI：10.1021/jp300765y

Colloidal Mn2+-doped semiconductor nanocrystals such as Mn2+:ZnSe have attracted broad attention for potential applications in phosphor and imaging technologies. Here, we report saturation of the sensitized Mn2+ photoluminescence intensity at very low continuous-wave (CW) and quasi-CW photoexcitation powers under conditions that are relevant to many of the proposed applications. Time-resolved photoluminescence measurements and kinetic modeling indicate that this saturation arises from an Auger-type nonradiative cross relaxation between an excited Mn2+ ion and an exciton within the same nanocrystal. A lower limit of k = 2 x 10(10) s(-1) is established for the fundamental rate constant of the Mn2+(T-4(1))-exciton cross relaxation.

• 出版日期2012-4-26