光电离导致CdTe量子点发光“关”态的直接证据
Direct evidence of photo-ionization causing luminescence "off" state in CdTe Quantum dots
摘要：
我们给出了光电离的CdTe量子点核在带边光激发下具有发光“关”态的直接实验证据。我们利用CdTe量子点在衍射极限检测体积中的稀胶体溶液的荧光涨落的自相关性来确定它们的光电离概率。电离概率与CdSe和CdSe/ZnS核/壳量子点处于相同的数量级（\approx 10-6）。此外，我们测量了加入β-硫醇后的电离/中和速率（\approx 104 s-1），发现加入β-硫醇后电离速率提高了两个数量级。然而，可比较的中和速率提高了光发射量子产率。微秒时间尺度的电离/中和对通过硫醇加成实现更好的量子产率提出了上限。结果还表明，在带边激发的主要电离机制是隧道。
英文摘要：
We present a direct experimental evidence of photo-ionized CdTe quantum dot core having luminescence "off" state at band-edge photo-excitation. We use the autocorrelation of fluorescence fluctuations from dilute colloidal solution of CdTe quantum dots in a diffraction limited detection volume to determine their photo-ionization probability. The ionization probability is in the same order of magnitude (\approx10-6) as the CdSe and CdSe/ZnS core/shell quantum dots. Further, we measured the ionization/ neutralization rates (\approx104 s-1) after addition of β-mercaptanol and found that ionization rate is enhanced by two orders of magnitude after the addition. However, a comparable neutralization rate enhances the light emission quantum yield. The ionization/ neutralization at microsecond time scales puts an upper limit on achieving better quantum yield by thiol addition. The results also indicate that the dominant ionization mechanism at band-edge excitation is tunneling.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
