Excitation-density and excess-energy dependence of ultrafast dynamics of photoexcited carriers in intrinsic bulk CdTe

Chen, Yicun; Shu, Tianyu; Lai, Tianshu; Wu, Huizhen

doi:10.1016/j.rinp.2021.105047

Cited by 3 publications

(4 citation statements)

References 30 publications

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“…Such a phenomenon can be attributed to the increasingly dominant role of the BGR effect in the competition between BGR and Burstein−Moss (BM) effects as the carrier density increased. 13,30 Furthermore, the high-energy PB enhanced with the higher carrier density, as shown in Figure 2d, suggesting that the Aguer process should play an important role in the origination of the high-energy PB at high photoexcited carrier density. 31,32 More detailed analysis will be presented in the following parts.…”

Section: Band Structures and Defect Densities In Cspbbrmentioning

confidence: 84%

“…This is another strong evidence for the existence of BGR. , The red shift of the PB peak became even more obvious at a higher carrier concentration, as shown in Figure d and its inset. Such a phenomenon can be attributed to the increasingly dominant role of the BGR effect in the competition between BGR and Burstein–Moss (BM) effects as the carrier density increased. , …”

Section: Resultsmentioning

confidence: 99%

“…A band-gap shrinkage magnitude of 10 and 7 meV for CsPbBr 3 microrods and microplates in the steady PL spectra, respectively, can be easily extracted (see Supporting Information (4)). The BGR effect causes band-gap shrinkage that is proportional to ( N ex ) 1/3 , according to the formula: Δ E g = − A · N ex 1/3 /ε s , , where A is a constant, N ex is the photoexcited carrier concentration, and ε s denotes a dielectric constant. Considering that the injected carrier density per unit time for pulse excitation in TA is approximately 5 orders of magnitude larger than that for continuous wave (CW) excitation in steady PL, the band-gap shrinkage magnitude of CsPbBr 3 microrods and microplates in TA spectra can be estimated to be about 480 and 336 meV, respectively (see Supporting Information (4) for details).…”

Section: Resultsmentioning

confidence: 99%

“…To design high-performance halide perovskites and devices, understanding carrier dynamics in these materials is one of the challenges faced by the scientific and industrial communities. It is widely argued that the many-body effects, resulting from electron–electron and electron–ionized impurity Coulombic interactions, play a key role in the electrical and optical properties in semiconductors, such as GaAs, CdTe, and PbTe. , Although the carrier dynamics in different semiconductors are well studied, research on halide perovskites is still ongoing. A band-gap renormalization (BGR) of about 3.7 meV was observed in CsPbBr 3 , which was due to the zero-point motion of Pb atoms .…”

Section: Introductionmentioning

confidence: 99%

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Giant Band-Gap Renormalization and Morphology-Tunable Defect-Assisted Carrier Recombination in CsPbBr₃ Microstructures

Yan,

Jiang,

Liu

et al. 2023

ACS Photonics

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Inorganic halide perovskite microstructures have presented intriguing potential for the development of highperformance optoelectronic devices. To advance the application of inorganic halide perovskite microstructures, it is crucial to understand the correlation between their morphologies and the dynamic properties of carriers. In this work, we investigated the carrier dynamics in CsPbBr 3 microrods and microplates primarily by using femtosecond transient absorption spectroscopy. Our results reveal a giant band-gap renormalization (BGR) effect originated from Coulombic enhancement, resulting in transient bandgap shrinkages as large as 480 and 336 meV for CsPbBr 3 microrods and microplates, respectively. The photoexcited carriers in both microstructures undergo four dynamic processes: thermalization and cooling, BGR, defect-assisted recombination, and Auger recombination. A proposed phenomenological model can be used to well analyze the dynamics and identify different time constants. The time constants for BGR are strongly dependent on pump fluence and probe wavelength, whereas the defect-assisted recombination time shows opposite fluence dependences in CsPbBr 3 microplates and microrods, respectively, due to the difference in defect densities between the two CsPbBr 3 microstructures. These findings provide new insights into the morphology-related carrier dynamics, particularly the many-body interactions in CsPbBr 3 microstructures, which offer potential applications in optoelectronic and photonic devices that benefit from their microstructure dimensions.

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