The fast hot-carrier cooling process in the solar-absorbers fundamentally limits their photon-conversion efficiencies. It is highly desirable to develop a solar absorber with long-lived hot-carriers at sun-illumination intensity, which can be used to develop the hot-carrier solar cells with enhanced efficiency. Herein, we reveal that zinc-doped (0.34 %) halide perovskites have the slower hot-carrier cooling compared with the pristine sample through the transient absorption spectroscopy measurements and theoretical calculations. The hot-carrier energy loss rate at the low photoexcitation level of 10 cm is found to be ≈3 times smaller than that of un-doped perovskites for T=500 K hot carriers, and up to ten times when the hot-carrier temperature approaches the lattice temperature. The incorporation of zinc-dopant into perovskites can reduce the nonadiabatic couplings between conduction bands, which retards the photogenerated hot-carriers relaxation processes. Our findings present a practical strategy to slow down the hot-carrier cooling in perovskites at low carrier densities, which would be invaluable for the further development of practical hot-carrier photovoltaics based on perovskites.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.202100099 | DOI Listing |
J Phys Chem Lett
December 2024
Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
The hot phonon bottleneck (HPB) effect has been proposed as one of the main phenomena behind the slow cooling in metal halide perovskites. Even though consensus has been reached regarding its existence, open questions remain concerning the HPB's specific applicability and potential regarding hot carrier solar cell (HCSC) applications. We present a full investigation using ensemble Monte Carlo simulations of the HPB effect in metal halide perovskites (MHP).
View Article and Find Full Text PDFAdv Mater
December 2024
Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
Metal halide perovskites have shown exceptionally slow hot-carrier cooling, which has been attributed to various physical mechanisms without reaching a consensus. Here, experiment and theory are combined to unveil the carrier cooling process in formamidinium (FA) and caesium (Cs) tin triiodide thin films. Through impulsive vibrational spectroscopy and molecular dynamics, much shorter phonon dephasing times of the hybrid perovskite, which accounts for the larger blueshift in the photoluminescence seen at high excitation density for FASnI compared to CsSnI is reported.
View Article and Find Full Text PDFNano Lett
December 2024
Department of Chemistry and Centre for Processible Electronics, Imperial College London, London W12 0BZ, United Kingdom.
Metallic MXenes are promising two-dimensional materials for energy storage, (opto)electronics, and photonics due to their high electrical conductivity and strong light-matter interaction. Energy dissipation in MXenes is fundamental for photovoltaic and photothermal applications. Here we apply ultrafast laser spectroscopy across a broad time range (femto- to microseconds) to study the cooling dynamics of electrons and lattice in emerging TiCT thin films compared to widely studied TiCT thin films.
View Article and Find Full Text PDFInorg Chem
December 2024
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Ternary ZnSeTe quantum dots (QDs) are regarded as the most promising Cd-free blue emitters, while their fundamental optical properties such as hot carrier (HC) cooling process and multiphoton absorption (MPA) remain unclear, which will hinder their potential application. In this work, we compare the HC cooling processes of ZnSeTe/ZnSeS and ZnSeTe/ZnSeS/ZnS QDs and find that the HC cooling times of ZnSeTe/ZnSeS/ZnS QDs are insensitive to excitation intensity as a result of the suppressed hot-phonon bottleneck and Auger effect. Importantly, we have determined the two- to five-photon absorption cross sections of two kinds of QDs, highlighting the advantages of ZnS shells in enhancing MPA cross sections of ZnSeTe-based QDs.
View Article and Find Full Text PDFJ Am Chem Soc
October 2024
Departments of Chemistry, and Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States.
Slowing hot carrier (HC) cooling and improving HC extraction are considered two pivotal factors for enhancing power conversion efficiency in emerging HC photovoltaic applications of perovskites and other materials. Employing ab initio quantum dynamics simulations, we demonstrate the simultaneous slow cooling and efficient extraction of hot electrons at the C/CsPbI interface through dipolar surface passivation with phenethylammonium and 4-fluorophenethylammonium ligands. The passivation effectively suppresses I-Pb lattice vibrations, weakens the hot electron-phonon interaction in CsPbI, and thus slows down the HC cooling.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!