The generation and transfer of triplet excitons across semiconductor nanomaterial–molecular interfaces will play an important role in emerging photonic and optoelectronic technologies, and understanding the rules that govern such phenomena is essential. The ability to cooperatively merge the photophysical properties of semiconductor quantum dots with those of well-understood and inexpensive molecular chromophores is therefore paramount. Here we show that 1-pyrenecarboxylic acid-functionalized CdSe quantum dots undergo thermally activated delayed photoluminescence. This phenomenon results from a near quantitative triplet–triplet energy transfer from the nanocrystals to 1-pyrenecarboxylic acid, producing a molecular triplet-state ‘reservoir’ that thermally repopulates the photoluminescent state of CdSe through endothermic reverse triplet–triplet energy transfer. The photoluminescence properties are systematically and predictably tuned through variation of the quantum dot–molecule energy gap, temperature and the triplet-excited-state lifetime of the molecular adsorbate. The concepts developed are likely to be applicable to semiconductor nanocrystals interfaced with molecular chromophores, enabling potential applications of their combined excited states.

三重态激子在半导体纳米材料-分子界面上的产生和转移将在新兴的光子和光电技术中发挥重要作用，因此了解控制这种现象的规则至关重要。因此，最重要的是将半导体量子点的光物理特性与众所周知的廉价分子发色团的光物理特性协同融合的能力。在这里，我们表明1-py羧酸官能化的CdSe量子点经历了热激活的延迟光致发光。这种现象是由于三重态-三重态三重态能量从纳米晶体到1-吡啶羧酸的转移所致，产生分子三重态“储库”，通过吸热反向三重态-三重态能量转移，热重新填充CdSe的光致发光状态。通过改变量子点-分子能隙，温度和分子被吸附物的三重态激发态寿命来系统地和可预测地调节光致发光特性。所开发的概念很可能适用于与分子发色团交界的半导体纳米晶体，从而可以潜在地应用其组合激发态。