Electron Transfer Dynamics from CsPbBr3 Nanocrystals to Au144 Clusters

Kritiman Marjit; Goutam Ghosh; Srijon Ghosh; Debarati Ghosh; Anusri Medda; Amitava Patra

doi:10.1021/acsphyschemau.2c00070

Electron Transfer Dynamics from CsPbBr₃ Nanocrystals to Au₁₄₄ Clusters

ACS Phys Chem Au. 2023 Feb 28;3(4):348-357. doi: 10.1021/acsphyschemau.2c00070. eCollection 2023 Jul 26.

Authors

Kritiman Marjit¹, Goutam Ghosh¹, Srijon Ghosh¹, Debarati Ghosh¹, Anusri Medda¹, Amitava Patra^{1

2}

Affiliations

¹ School of Materials Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
² Institute of Nano Science and Technology, Knowledge City, Sector 81, Mohali 140306, India.

Abstract

Lead halide perovskite nanocrystals have received significant attention as an absorber material for designing efficient optoelectronic devices. The fundamental understanding of the hot carrier (HC) dynamics as well as its extraction in hybrid systems is essential to further boost the performance of solar cells. Herein, we have explored the electron transfer dynamics in the CsPbBr₃-Au₁₄₄ cluster hybrid using ultrafast transient absorption spectroscopy. Our analysis reveals faster HC cooling time (from 515 to 334 fs) and a significant drop in HC temperature from 1055 to 860 K in hybrid, suggesting the hot electron transfer from CsPbBr₃ nanocrystals to the Au nanoclusters (NCs). Eventually, we observe a much faster hot electron transfer compared to the band-edge electron transfer, and 45% hot-electron transfer efficiency was achieved at 0.64 eV, above band-edge photoexcitation. Furthermore, the significant enhancement of the photocurrent to the dark current ratio in this hybrid system confirms the charge separation via the electron transfer from CsPbBr₃ nanocrystals to Au₁₄₄ NCs. These findings on HC dynamics could be beneficial for optoelectronic devices.