Single-dot spectroscopy uncovers the effects of surface trapping and Auger recombination on quantum dot emission

Abstract

Surface trapping and Auger recombination typically suppress the emission of quantum dots (QDs). Understanding how these two processes affect the emission properties of QDs is critical to optimizing their photoluminescence (PL) performance. However, isolating their respective contributions can be challenging. In this study, we investigate the respective effects of surface trapping and Auger recombination on QD emission using single QD spectroscopy. The effects of surface trapping and Auger recombination on QD emission can be distinguished by analyzing the real-time changes in the radiative and non-radiative rates of the PL trajectories of single QDs. This is because Auger recombination can alter both the radiative and non-radiative rates, while surface trapping changes only the non-radiative rate. We find that when the PL trajectory of a single QD is in a gray state due to surface trapping, it can still exhibit Auger blinking induced by charging. Surface trapping introduces non-radiative recombination pathways not only for neutral exciton states but also for trion states. This further confirms that surface trapping and Auger recombination in QDs are completely independent non-radiative pathways. The ability to distinguish the respective effects of Auger recombination and surface trapping provides valuable insights into QD emission mechanisms.

Graphical abstract

Keywords

single quantum dot / surface trap / Auger recombination / photoluminescence blinking

1 Introduction

Colloidal semiconductor quantum dots (QDs) are at the forefront of optoelectronic technologies, including light-emitting diodes, lasers, photovoltaic cells, biomedical labeling, and quantum technologies, due to their exceptional photoluminescence (PL) quantum yields, broad absorption spectra, and narrow emission bands [1-4]. These remarkable properties were recognized with the 2023 Nobel Prize in Chemistry for the development of QDs. However, the high surface-to-volume ratio and small size of QDs make them particularly susceptible to surface trapping and Auger recombination, both of which can significantly degrade their optical and electronic properties [5-7]. Surface trapping occurs when charge carriers (electrons and holes) are trapped on the QD surface, leading to PL quenching and shortened carrier lifetimes. Auger recombination, on the other hand, is a non-radiative process in which the energy from electron-hole recombination is transferred to a third carrier, resulting in thermal relaxation and energy dissipation as heat, resulting in PL quenching and reduced carrier lifetime [8-10]. Therefore, traditional measurements of PL intensity and lifetime in ensemble QDs are challenging to distinguish the individual contributions of these processes. Such a distinction is critical to guide the design of QDs to enhance their emission properties.

Both Auger recombination and surface trapping cause the phenomenon of PL blinking of single QDs, i.e., the PL emission randomly switches between bright (“on”) and dark (“off”) states [11-17]. In the case of Auger recombination, PL blinking occurs due to photoionization and neutralization of a single QD, where the “on” state corresponds to radiative recombination of excitons within a neutral QD, and the “off” state corresponds to reduced PL intensity due to non-radiative Auger recombination [18-22]. In the case of surface trapping, PL blinking occurs due to the activation and deactivation of short-lived surface traps that non-radiatively trap band-edge carriers, resulting in a continuous variation of PL intensity [23-29]. Advanced methods have been developed to distinguish between these mechanisms, with variations in radiative lifetime indicating Auger-blinking and constant radiative lifetime indicating band-edge carrier (BC) blinking [30]. Our previous research has not only regulated Auger-blinking and BC-blinking, but also explored their effects on biexciton dynamics [31-35]. Despite this progress in controlling these observable phenomena, a long-standing challenge regarding the photophysics of colloidal QDs persists: both surface trapping and Auger recombination contribute to reduced PL intensity and lifetime, making it difficult to distinguish between them.

In this study, we use single QD spectroscopy to investigate the respective effects of surface trapping and Auger recombination on QD emission. By analyzing the real-time changes in the radiative and non-radiative rates, we are able to capture the radiative and non-radiative rate trajectories of single QDs over time, which allows us to distinguish between the effects of surface trapping and Auger recombination. This is because Auger recombination can change both the radiative and non-radiative rates, while surface trapping only changes the non-radiative rate. Our analysis of the non-radiative rate trajectories shows that surface trapping and Auger recombination in QDs are completely independent non-radiative pathways. We find that surface trapping introduces non-radiative recombination pathways not only for neutral exciton states but also for trion states. Thus, the study of the non-radiative recombination process induced by surface trapping can be extended beyond the neutral exciton states to the trion states, providing a more comprehensive understanding of the underlying mechanisms.

2 Experimental section

To investigate the PL properties of single QDs and eliminate the ensemble averaging effects that mask single-dot behaviors such as PL blinking and spectral diffusion, we performed single-QD spectroscopy measurements. This technique allows for the optical interrogation of one QD at a time, providing direct access to its intrinsic photophysics. The single-QD measurements were conducted using a home-built confocal microscope based on an inverted optical frame. A pulsed laser (repetition rate: 5 MHz, wavelength: 485 nm) was used for excitation. The laser beam was focused onto the sample through a high numerical aperture (N.A. = 1.3) oil-immersion objective. The same objective collected the PL emission, which was separated from the excitation laser by a dichroic mirror. A long-pass filter further filtered the emitted light to block any residual laser light before directing it to the detection path.

Isolating a single QD was achieved through a combination of low sample density and spatial filtering. First, a highly dilute solution of QDs was spin-coated onto a clean glass coverslip to prepare the QD sample, resulting in a surface density of less than 0.1 QDs/µm². This low density ensures that, within the diffraction-limited laser spot (~300 nm in diameter), the probability of finding more than one QD is statistically negligible. Second, the confocal setup provides spatial filtering via a 100 µm pinhole that blocks out-of-focus light, ensuring that only emission from the confocal volume is detected. To confirm that the measured signals originated from a single QD and not from aggregates, second-order correlation function [g⁽²⁾(τ)] measurements were performed using a Hanbury Brown and Twiss (HBT) interferometer [36]. A pronounced antibunching dip at zero time delay [g⁽²⁾(0) < 0.5] was consistently observed (Fig. S1), which is the hallmark of a single quantum emitter.

For time-resolved PL blinking measurements, the PL signal was split and detected by two single-photon avalanche diodes. Photon arrival times were recorded using a time-tagged, time-correlated single-photon counting (TTTR-TCSPC) module. The resulting time trace was binned into 10 ms intervals to construct a PL intensity trajectory, revealing the characteristic ‘on’ and ‘off’ periods of PL blinking. We then extracted the PL lifetime from the photon arrival times within the ‘on’ and ‘off’ states to analyze the distinct recombination dynamics.

3 Results and discussion

A typical trajectory of PL intensity as a function of time collected from a single QD (alloyed CdSe/Cd_xZn_1−xS core/shell QDs; the TEM image, absorption and emission spectra, and sample preparation method can be found in our previous published work [35]) is shown in Fig. 1(a). It can be seen that the PL blinking behavior in the green-shaded region is very different from that in the yellow-shaded region. In the green-shaded region, the PL intensity has a stable bright state with an intensity around 25 kcounts/s and a dim state of very short duration with an intensity around 10 kcounts/s. In contrast, in the yellow-shaded region, the PL intensity contains multiple states, each of which lasts significantly longer than the dim state in the green region. Here we use radiative lifetime scaling to distinguish the origin of these different emission states. Theoretically, the radiative lifetime scaling between the neutral exciton state and the trion state should be 2 [30]. This is due to the fact that in the neutral exciton state there is only one electron and one hole, which allows for only one recombination pathway. In contrast, in the trion state there are either two electrons and one hole or one electron and two holes, leading to two distinct recombination pathways. The diagrams inserted in Fig. 1(a) depict the radiative and non-radiative recombination pathways for the neutral exciton and trion states. Experimentally, the radiative lifetime scaling is usually obtained by measuring the PL intensity and lifetime of each state. Figure 1(b) shows the corresponding PL decay curves extracted from the rectangular areas of different colors in Fig. 1(a). They were fitted by single exponential functions with {\tau }_1=24.4\mathrm{n}\mathrm{s} (blue), {\tau }_2=9.9\mathrm{n}\mathrm{s} (purple), and {\tau }_3=5.1\mathrm{n}\mathrm{s} (red), respectively. It can be obtained from Fig. 1(a) that the PL intensities indicated by the blue, purple, and red rectangles are I_1=25\mathrm{k}\mathrm{c}\mathrm{o}\mathrm{u}\mathrm{n}\mathrm{t}\mathrm{s}/\mathrm{s}, I_2=10.5\mathrm{k}\mathrm{c}\mathrm{o}\mathrm{u}\mathrm{n}\mathrm{t}\mathrm{s}/\mathrm{s}, and I_3=9.5\mathrm{k}\mathrm{c}\mathrm{o}\mathrm{u}\mathrm{n}\mathrm{t}\mathrm{s}/\mathrm{s}, respectively. Therefore, the radiative lifetime scaling between the blue and purple rectangles is

{\displaystyle \frac{{\tau }_{\mathrm{r}1}}{{\tau }_{\mathrm{r}2}}}={\displaystyle \frac{{\tau }_1}{{\tau }_2}}{\displaystyle \frac{I_2}{I_1}}={\displaystyle \frac{24.4}{9.9}}\times {\displaystyle \frac{10.5}{25}}\approx 1.

The radiative lifetime scaling of ~1 indicates that the trajectories in the blue and purple rectangles correspond to the neutral exciton states (Exciton1 and Exciton2). The decline in PL intensity observed in the purple rectangle is attributed to the occurrence of non-radiative recombination. The radiative lifetime scaling between blue and red rectangles is

{\displaystyle \frac{{\tau }_{\mathrm{r}1}}{{\tau }_{\mathrm{r}3}}}={\displaystyle \frac{{\tau }_1}{{\tau }_3}}{\displaystyle \frac{I_3}{I_1}}={\displaystyle \frac{24.4}{5.1}}\times {\displaystyle \frac{9.5}{25}}\approx \mathrm{1.82.}

The radiative lifetime scaling of 1.82, which is close to the theoretical value of 2, indicating that the red rectangle corresponds to a trion state. The discrepancy between the experimental value of 1.82 and the theoretical value of 2 can be attributed to the larger wave function overlap between electrons and holes in the neutral states compared to the trion states [37, 38].

The PL lifetime-intensity distribution diagrams for the green-shaded and yellow-shaded regions are shown in Figs. 1(c) and (d), respectively, which are powerful tools for distinguishing blinking mechanisms [15, 30, 35]. Figure 1(c) shows a nonlinear correlation between PL intensity (I) and lifetime (\tau). The nonlinear correlation is simulated by I=\frac{I_1{I}_3\left({\tau }_1-{\tau }_3\right)}{I_3\left({\tau -\tau }_3\right)+I_1\left({\tau }_1-\tau \right)} [21, 34], as shown by the white solid line. Therefore, the green-shaded region in Fig. 1(a) correspond to Auger-blinking [34]. Figure 1(d) shows a linear correlation between PL intensity and lifetime. This linearity is due to the constant radiative decay rate k_r (or radiative lifetime {\tau }_{\mathrm{r}}) and the fluctuating non-radiative rates k_nr(t), as simulated by the formula I\propto QY=\frac{k_{\mathrm{r}}}{k_{\mathrm{r}}+k_{\mathrm{n}\mathrm{r}}\left(t\right)}=\frac{\tau }{{\tau }_{\mathrm{r}}}, as shown by the white solid line [23, 34]. Therefore, the yellow-shaded region in Fig. 1(a) correspond to BC-blinking [23].

The PL intensity trajectory in Fig. 1 shows distinct blinking types corresponding to different time regions. The two blinking types are clearly separated in time and therefore be visually distinguished using the PL lifetime-intensity distribution. Nevertheless, in most cases the BC-blinking and Auger-blinking of a single QD do not exhibit such a clear temporal separation, but rather they are mixed together. For this case, there is a need to develop a robust method to effectively distinguish between the effects of surface trapping and Auger recombination on the emission properties of QDs.

Figure 2(a) shows representative PL intensity (black line) and lifetime (red line) trajectories for a single QD with an integration time of 10 ms. A PL decay histogram was constructed for each interval, and the lifetime was extracted by calculating the mean photon arrival time. This provides a direct estimate of the lifetime under our experimental conditions. Unlike Fig. 1(a), Fig. 2(a) shows an irregular PL intensity trajectory, which may be due to a mixing of BC- and Auger-blinking. An effective distinction between neutral exciton states and trion states is necessary to study the effects of surface trapping and Auger recombination on QD emission properties.

Whether the radiative lifetime (τ_r) changes during the fluctuation of PL intensity (I) and lifetime (τ) is a powerful tool to distinguish between neutral exciton and trion states. In the PL intensity trajectory of a single QD, the maximum PL intensity (I_{\mathrm{m}\mathrm{a}\mathrm{x}}) typically represents a quantum yield (QY) of 1 [39], from which the QY of other PL intensity states can be calculated as \mathrm{Q}\mathrm{Y}=\frac{I_{\mathrm{m}\mathrm{a}\mathrm{x}}}{I}. The radiative lifetime can then be calculated as {\tau }_{\mathrm{r}}=\tau \frac{1}{\mathrm{Q}\mathrm{Y}}. Figure 2(b) shows the calculated radiative lifetime trajectory, where QY and τ are obtained from Fig. 2(a). For the very low intensity states in the PL trajectory, the shot noise will have a larger effect on the calculation of the radiative lifetime. Therefore, the corresponding radiative lifetimes for very low PL intensities are not shown in Fig. 2(b). The corresponding radiative lifetime histogram is shown in the right panel of Fig. 2(b). The peaks of the histogram correspond to radiative lifetimes of 19 ns and 12 ns. The radiative lifetime scaling between them is 1.6, which is close to the theoretical value of 2 [37], despite some reasonable deviations. Therefore, the radiative lifetimes of 19 ns and 12 ns originate from the neutral (red dashed line) and trion (blue dashed line) states, respectively. The main reason for the discrepancy between the experimental and theoretical radiation lifetime scaling values is the reduced spatial overlap between the electron and hole wave functions in the negative trion state compared to the neutral exciton state (see Supplementary Note 1 for a detailed discussion) [37]. By taking the inverse of the radiative lifetimes in Fig. 2(b), we can obtain the trajectory of the radiative recombination rate (k_{\mathrm{r}}) (green line) shown in Fig. 2(d).

After distinguishing between the neutral exciton states and the trion states, we investigate the effects of surface trapping and Auger recombination on the QD emission. From Figs. 2(a) and (b), it can be observed that although the PL intensity and lifetime of the neutral state fluctuate due to the activation and deactivation of surface traps [Fig. 2(a)], the radiative lifetime of the trion state (blue dashed line) is kept around 12 ns [Fig. 2(b)]. This means that surface traps do not affect the radiative recombination dynamics of the trion states.

The non-radiative rate (k_{\mathrm{n}\mathrm{r}}) and the non-radiative lifetime ({\tau }_{\mathrm{n}\mathrm{r}}) can be calculated as k_{\mathrm{n}\mathrm{r}}=k-k_{\mathrm{r}},\mathrm{a}\mathrm{n}\mathrm{d}{\tau }_{\mathrm{n}\mathrm{r}}=\frac{1}{k_{\mathrm{n}\mathrm{r}}}, where k is the inverse of the lifetime, the total rate. Figures 2(c) and (d) show the corresponding non-radiative lifetime trajectory and the non-radiative rate trajectory (black line), respectively. It can be seen that the changes in the non-radiative lifetimes [Fig. 2(c)] correspond to the fluctuations in the PL intensity [Fig. 2(a)], i.e., the non-radiative lifetime trajectory is very similar to that of PL intensity. This suggests that the variations in PL intensity are mainly caused by changes in the non-radiative recombination rather than the radiative recombination. As shown in Fig. 2(d), the change in the radiative rate is small, while the non-radiative rate exhibits a very broad distribution. It can also be seen from Fig. 2(d) that when the non-radiative rate of the neutral exciton state (red dashed line) increases, the non-radiative rate of the corresponding trion state (blue dashed line) also increases by the same amount. This observation highlights the fact that the non-radiative rate of the trion state is composed of two components: the non-radiative Auger rate and the non-radiative rate due to surface traps.

Based on the above experimental results, we have drawn a schematic illustration of the effects of surface trapping and Auger recombination on the emission properties of CdSe/Cd_xZn_1−xS core/shell QDs, as shown in Fig. 3. Figure 3(a) shows the neutral state with surface traps inactivated, in which the exciton undergoes only radiative recombination with a QY of 1. The corresponding lifetime ({\tau }_{\mathrm{a}}) is {\tau }_{\mathrm{a}}=\frac{1}{k_{\mathrm{r}}}, where k_{\mathrm{r}} is the radiative recombination rate of single exciton. Figure 3(b) shows the neutral state with surface traps activated, in which the exciton can also relax non-radiatively through surface traps. The corresponding lifetime ({\tau }_{\mathrm{b}}) is {\tau }_{\mathrm{b}}=\frac{1}{k_{\mathrm{r}}+k_{\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{p}}}, where k_{\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{p}} is the non-radiative rate due to surface traps. The state transition between Fig. 3(a) and Fig. 3(b) corresponds to BC-blinking. Figure 3(c) shows the trion state with surface traps inactivated, where both electrons have the opportunity to recombine with a hole and thus the radiative rate is twice that of a single exciton. In the trion state, Auger non-radiative recombination quenches the emission by transferring the exciton energy to the third carrier. The corresponding lifetime ({\tau }_{\mathrm{c}}) is {\tau }_{\mathrm{c}}=\frac{1}{{2k}_{\mathrm{r}}+k_{\mathrm{A}}}, where k_{\mathrm{A}} is the non-radiative Auger rate. The state transition between Fig. 3(a) and Fig. 3(c) corresponds to Auger-blinking. Figure 3(d) shows the trion state with surface traps activated, which includes all radiative and non-radiative recombination pathways mentioned above. The corresponding lifetime ({\tau }_{\mathrm{d}}) is {\tau }_{\mathrm{d}}=\frac{1}{{2k}_{\mathrm{r}}+k_{\mathrm{A}}+k_{\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{p}}}. In most cases, the k_{\mathrm{A}} is much faster than k_{\mathrm{r}} and k_{\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{p}}, which means that the Auger process severely suppresses the trion’s quantum yield, making the additional quenching from k_{\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{p}} a secondary, less significant effect. Therefore, the effect of surface traps on the PL intensity and lifetime of the trion state appears to be weaker than their effect on the neutral state. The state transition between Fig. 3(b) and Fig. 3(d) corresponds to Auger-blinking and the state transition between Fig. 3(c) and Fig. 3(d) corresponds to BC-blinking. For a single QD, the value of k_{\mathrm{A}} are fixed, while the value of k_{\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{p}} fluctuates. Therefore, Auger-blinking usually appears as a binary alternation between bright and dark states due to the fixed k_{\mathrm{A}}, while BC-blinking appears as a continuous PL intensity variation due to the fluctuating k_{\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{p}}.

4 Conclusions

We have used single QD spectroscopy to investigate the respective effects of surface trapping and Auger recombination on QD emission. By analyzing real-time changes in the radiative and non-radiative rates of the blinking trajectories, we are able to distinguish their respective contributions for the first time. Variations in the radiative rate serve as an indicator of the effect of Auger recombination on QD emission. Our results demonstrate that, even when a single QD is in a gray state due to surface trapping, it can exhibit simultaneous Auger blinking due to charging. Furthermore, surface trapping introduces non-radiative recombination pathways for the both neutral exciton and trion states, confirming that surface trapping and Auger recombination are independent non-radiative pathways in QDs. By decoupling these two major non-radiative pathways, our work provides a definitive framework for understanding QD emission dynamics. This fundamental clarification not only resolves a long-standing challenge in the field but also advances the rational design of novel QD materials. Future strategies can target surface passivation to mitigate trapping and engineer electronic structures to independently suppress Auger recombination, paving the way for QD-based optoelectronic devices with near-unity quantum yields and perfect stability.

References

[1] F. P. García de Arquer , D. V. Talapin , V. I. Klimov , Y. Arakawa , M. Bayer , and E. H. Sargent , Semiconductor quantum dots: Technological progress and future challenges, Science 373(6555), eaaz8541 (2021)

[2] D. Feng , G. Zhang , and Y. Li , Semiconductor quantum dots: Synthesis, properties and applications, Nanomaterials (Basel) 14(22), 1825 (2024)

[3] S. M. Hosseiny , J. Seyed-Yazdi , and M. Norouzi , Quantum teleportation and remote sensing through semiconductor quantum dots affected by pure dephasing, Front. Phys. (Beijing) 20(2), 024201 (2025)

[4] C. Yang , G. Zhang , J. Li , R. Chen , C. Qin , J. Hu , Z. Yang , L. Xiao , and S. Jia , Mechanisms and suppression of quantum dot blinking, Laser Photonics Rev. 19(9), 2402269 (2025)

[5] C. R. Kagan , E. Lifshitz , E. H. Sargent , and D. V. Talapin , Building devices from colloidal quantum dots, Science 353(6302), aac5523 (2016)

[6] Y. H. Lin,N. Sakai,P. Da,J. Wu,H. C. Sansom,A. J. Ramadan,S. Mahesh,J. Liu,R. D. J. Oliver,J. Lim,L. Aspitarte,K. Sharma,P. K. Madhu,A. B. Morales-Vilches,P. K. Nayak,S. Bai,F. Gao,C. R. M. Grovenor,M. B. Johnston,J. G. Labram,J. R. Durrant,J. M. Ball,B. Wenger,B. Stannowski,H. J. Snaith, A piperidinium salt stabilizes efficient metal-halide perovskite solar cells, Science 369(6499), 96 (2020)

[7] J. Bao,M. G. Bawendi, A colloidal quantum dot spectrometer, Nature 523(7558), 67 (2015)

[8] Y. Yang , J. Li , Y. Li , B. Li , J. Zhang , Z. Chen , L. Xiao , R. Lai , Z. Zeng , G. Zhang , and B. Ji , High-purity single-photon emission in near-infrared InAs colloidal quantum dots with strong exciton confinement, Nano Lett. 25(18), 7595 (2025)

[9] X. Han , Z. Huang , G. Zhang , C. Yang , J. Li , M. Zhang , Z. Chen , J. Wang , R. Chen , C. Qin , J. Hu , Z. Yang , X. Liu , Y. Wang , J. Ma , L. Xiao , and S. Jia , Ultrafast exciton formation in perovskite quantum rods, Nano Lett. 25(12), 4913 (2025)

[10] T. Kim , Y. H. Won , E. Jang , and D. Kim , Negative trion Auger recombination in highly luminescent InP/ZnSe/ZnS quantum dots, Nano Lett. 21(5), 2111 (2021)

[11] B. Li , G. Zhang , Y. Gao , X. Chen , R. Chen , C. Qin , J. Hu , R. Wu , L. Xiao , and S. Jia , Single quantum dot spectroscopy for exciton dynamics, Nano Res. 17(12), 10332 (2024)

[12] M. Nirmal , B. O. Dabbousi , M. G. Bawendi , J. J. Macklin , J. K. Trautman , T. D. Harris , and L. E. Brus , Fluorescence intermittency in single cadmium selenide nanocrystals, Nature 383(6603), 802 (1996)

[13] J. Zhou , A. I. Chizhik , S. Chu , and D. Jin , Single-particle spectroscopy for functional nanomaterials, Nature 579(7797), 41 (2020)

[14] C. Yang , G. Zhang , Y. Gao , B. Li , X. Han , J. Li , M. Zhang , Z. Chen , Y. Wei , R. Chen , C. Qin , J. Hu , Z. Yang , G. Zeng , L. Xiao , and S. Jia , Size-dependent photoluminescence blinking mechanisms and volume scaling of biexciton Auger recombination in single CsPbI₃ perovskite quantum dots, J. Chem. Phys. 160(17), 174505 (2024)

[15] J. Li , D. Wang , G. Zhang , C. Yang , W. Guo , X. Han , X. Bai , R. Chen , C. Qin , J. Hu , L. Xiao , and S. Jia , The role of surface charges in the blinking mechanisms and quantum-confined stark effect of single colloidal quantum dots, Nano Res. 15(8), 7655 (2022)

[16] G. F. Zhang , C. G. Yang , Y. Ge , Y. G. Peng , R. Y. Chen , C. B. Qin , Y. Gao , L. Zhang , H. Z. Zhong , Y. J. Zheng , L. T. Xiao , and S. T. Jia , Influence of surface charges on the emission polarization properties of single CdSe/CdS dot-in-rods, Front. Phys. (Beijing) 14(6), 63601 (2019)

[17] G. Zhang , Y. Peng , H. Xie , B. Li , Z. Li , C. Yang , W. Guo , C. Qin , R. Chen , Y. Gao , Y. J. Zheng , L. T. Xiao , and S. T. Jia , Linear dipole behavior of single quantum dots encased in metal oxide semiconductor nanoparticles films, Front. Phys. (Beijing) 14(2), 23605 (2019)

[18] R. Meng , H. Qin , Y. Niu , W. Fang , S. Yang , X. Lin , H. Cao , J. Ma , W. Lin , L. Tong , and X. Peng , Charging and discharging channels in photoluminescence intermittency of single colloidal CdSe/CdS core/shell quantum dot, J. Phys. Chem. Lett. 7(24), 5176 (2016)

[19] H. Y. Qin , R. Y. Meng , N. Wang , and X. G. Peng , Photoluminescence intermittency and photo-bleaching of single colloidal quantum dot, Adv. Mater. 29(14), 1606923 (2017)

[20] C. Yang , R. Xiao , S. Zhou , Y. Yang , G. Zhang , B. Li , W. Guo , X. Han , D. Wang , X. Bai , J. Li , R. Chen , C. Qin , J. Hu , L. Feng , L. Xiao , and S. Jia , Efficient, stable, and photoluminescence intermittency-free CdSe-based quantum dots in the full-color range, ACS Photonics 8(8), 2538 (2021)

[21] C. Galland , Y. Ghosh , A. Steinbrück , M. Sykora , J. A. Hollingsworth , V. I. Klimov , and H. Htoon , Two types of luminescence blinking revealed by spectro-electrochemistry of single quantum dots, Nature 479(7372), 203 (2011)

[22] B. Li , Y. Gao , R. Wu , X. Miao , and G. Zhang , Charge and energy transfer dynamics in single colloidal quantum dots/monolayer MoS₂ heterostructures, Phys. Chem. Chem. Phys. 25(11), 8161 (2023)

[23] P. A. Frantsuzov , S. Volkan-Kacso , and B. Janko , Model of fluorescence intermittency of single colloidal semiconductor quantum dots using multiple recombination centers, Phys. Rev. Lett. 103(20), 207402 (2009)

[24] A. A. Cordones and S. R. Leone , Mechanisms for charge trapping in single semiconductor nanocrystals probed by fluorescence blinking, Chem. Soc. Rev. 42(8), 3209 (2013)

[25] R. Schmidt , C. Krasselt , C. Göhler , and C. von Borczyskowski , The fluorescence intermittency for quantum dots is not power-law distributed: A luminescence intensity resolved approach, ACS Nano 8(4), 3506 (2014)

[26] S. Sampat , N. S. Karan , T. Guo , H. Htoon , J. A. Hollingsworth , and A. V. Malko , Multistate blinking and scaling of recombination rates in individual silica-coated CdSe/CdS nanocrystals, ACS Photonics 2(10), 1505 (2015)

[27] K. Zhang , H. Chang , A. Fu , A. P. Alivisatos , and H. Yang , Continuous distribution of emission states from single CdSe/ZnS quantum dots, Nano Lett. 6(4), 843 (2006)

[28] M. Zhang , X. Han , C. Yang , G. Zhang , W. Guo , J. Li , Z. Chen , B. Li , R. Chen , C. Qin , J. Hu , Z. Yang , G. Zeng , L. Xiao , and S. Jia , Size uniformity of CsPbBr₃ perovskite quantum dots via manganese-doping, Nanomaterials (Basel) 14(15), 1284 (2024)

[29] X. Bai , H. Li , Y. Peng , G. Zhang , C. Yang , W. Guo , X. Han , J. Li , R. Chen , C. Qin , J. Hu , G. Yang , H. Zhong , L. Xiao , and S. Jia , Role of aspect ratio in the photoluminescence of single CdSe/CdS dot-in-rods, J. Phys. Chem. C 126(5), 2699 (2022)

[30] G. Yuan , D. E. Gómez , N. Kirkwood , K. Boldt , and P. Mulvaney , Two mechanisms determine quantum dot blinking, ACS Nano 12(4), 3397 (2018)

[31] W. Guo , J. Li , B. Li , W. Zhang , C. Yang , X. Han , Z. Chen , G. Yang , Z. Yang , R. Chen , C. Qin , J. Hu , G. Zhang , and L. Xiao , Measurement of absolute biexciton quantum yields in single quantum dots: Breaking the limitation of weak excitation conditions, Appl. Phys. Lett. 127(5), 052104 (2025)

[32] B. Li , H. Huang , G. Zhang , C. Yang , W. Guo , R. Chen , C. Qin , Y. Gao , V. P. Biju , A. L. Rogach , L. Xiao , and S. Jia , Excitons and biexciton dynamics in single CsPbBr₃ perovskite quantum dots, J. Phys. Chem. Lett. 9(24), 6934 (2018)

[33] X. Han , G. Zhang , B. Li , C. Yang , W. Guo , X. Bai , P. Huang , R. Chen , C. Qin , J. Hu , Y. Ma , H. Zhong , L. Xiao , and S. Jia , Blinking mechanisms and intrinsic quantum-confined stark effect in single methylammonium lead bromide perovskite quantum dots, Small 16(51), 2005435 (2020)

[34] C. Yang , Y. Li , X. Hou , M. Zhang , G. Zhang , B. Li , W. Guo , X. Han , X. Bai , J. Li , R. Chen , C. Qin , J. Hu , L. Xiao , and S. Jia , Conversion of photoluminescence blinking types in single colloidal quantum dots, Small 20(23), 2309134 (2024)

[35] B. Li , G. Zhang , Y. Zhang , C. Yang , W. Guo , Y. Peng , R. Chen , C. Qin , Y. Gao , J. Hu , R. Wu , J. Ma , H. Zhong , Y. Zheng , L. Xiao , and S. Jia , Biexciton dynamics in single colloidal CdSe quantum dots, J. Phys. Chem. Lett. 11(24), 10425 (2020)

[36] Y. Hu , T. Ma , D. Mao , Z. Wang , W. Zhou , H. Xu , H. Dong , and W. Xie , Simulation of temporal second-order correlation function based on Monte Carlo algorithm, Front. Phys. (Beijing) 20(3), 034204 (2025)

[37] Y. S. Park , W. K. Bae , J. M. Pietryga , and V. I. Klimov , Auger recombination of biexcitons and negative and positive trions in individual quantum dots, ACS Nano 8(7), 7288 (2014)

[38] K. F. Wu , J. Lim , and V. I. Klimov , Superposition principle in Auger recombination of charged and neutral multicarrier states in semiconductor quantum dots, ACS Nano 11(8), 8437 (2017)

[39] X. Brokmann , L. Coolen , M. Dahan , and J. P. Hermier , Measurement of the radiative and nonradiative decay rates of single CdSe nanocrystals through a controlled modification of their spontaneous emission, Phys. Rev. Lett. 93(10), 107403 (2004)

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