Enhanced Valley Splitting of Exciton Emission in Colloidal PbSe Quantum Dots When the Interdot Distance Coincides with Onset of Forster Resonance Energy Transfer
Enhanced Valley Splitting of Exciton Emission in Colloidal PbSe Quantum Dots When the Interdot Distance Coincides with Onset of Forster Resonance Energy Transfer
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当点间距离与福斯特共振能量转移的开始一致时，胶体 PbSe 量子点中激子发射的增强谷分裂
DOI：
10.1021/acs.jpclett.1c00165
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Kita Masao
中科院分区：
文献类型：
--
作者：
Omata Takahisa;Asano Hiroshi;Sakai Masahiro;Terai Yoshikazu;Kita Masao
研究了胶体PbSe/CdSe核/壳量子点(量子点，CdSe壳层厚度：0.2nm.2 nm)在室温和不同量子点间距(L=7~2 40 nm)下的最低激子态发光。随着L的降低，PbSe量子点的能级分裂明显增强。同时，当L值仍然足够大时(7 nm≤L≤50 nm)，不同量子点的波函数不重叠时，由于Fo-QD共振能量转移(FRET)，发射发生了红移。在无明显外场的情况下，增强裂谷作为一种控制裂谷的方法是非常有趣的。导致FRET的电子耦合可能会增强山谷分裂，因为它发生在L的相同范围内。
Photoluminescence (PL) emission of colloidal PbSe/CdSe core/shell quantum dots (QDs, CdSe shell thickness: 0.2 nm) at the lowest exciton state was investigated at room temperature and varying inter-QD distance (L= 7–240 nm) by changing the QD concentration. A distinct enhancement of the valley splitting of PbSe QDs was observed upon reducingL. Simultaneously, there was a redshift in the emission due to Förster resonance energy transfer (FRET), when theLvalue was still sufficiently large (7 nm ≤L≤ 50 nm) so that the wave functions of different QDs do not overlap. The enhanced valley splitting under no apparent external field is quite interesting as a method to control the valley splitting. The electronic coupling leading to FRET may enhance the valley splitting, because it occurs in an identical range ofL.