Fast hot-carrier cooling process in the solar-absorbers fundamentally limits the photon-energy conversion efficiencies. It is highly desirable to develop the solar absorber with long-lived hot-carriers at sun-illumination level, 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 17 cm -3 is found to be ~3 times smaller than that of un-doped perovskites for 500-K hot carriers, and up to ten times when the hot-carrier temperature approaching 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 process. Our findings present a practical strategy to slow down the hot-carrier cooling in perovskites at low carrier densities, which are valuable for the further development of practical perovskite hot-carrier photovoltaics .
Bibliographical noteKAUST Repository Item: Exported on 2021-03-01
Acknowledgements: Q.W. and J. Y. contributed equally to this w ork. Q.W. thanks the support from the Natural Science Foundation of China (61904152) and the China Postdoctoral Science Foundation (2019M653721). The Project supported by the Natural Science Foundation of Guangdong Province, China (Grant No. 2019A1515012186). G. X. acknow ledges the financial supported by Macau Science and Technology Development Funds (FDCT091/2017/A2, FDCT-014/2017/AMJ), Research Grants (MYRG2018-00148-IAPME) from University of Macau, the Natural Science Foundation of China (91733302, 61605073, 61935017). M.J.L. acknow ledges the financial support from Hong Kong Polytechnic University (Grant No. 1-BE2Z and 1- ZVGH). J. Y., O. M. B., and O. F. M. acknow ledge the Supercomputing Laboratory at KAUST for their computational
and storage resources, as w ell as their efficient technical assistance.