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Abstract Tuning the properties of a pair of entangled electron and hole in a light-induced exciton is a fundamentally intriguing inquiry for quantum science. Here, using semiconducting hybrid perovskite as an exploratory platform, we discover that Nd2+-doped CH3NH3PbI3(MAPbI3) perovskite exhibits a Kondo-like exciton-spin interaction under cryogenic and photoexcitation conditions. The feedback to such interaction between excitons in perovskite and the localized spins in Nd2+is observed as notably prolonged carrier lifetimes measured by time-resolved photoluminescence, ~10 times to that of pristine MAPbI3without Nd2+dopant. From a mechanistic standpoint, such extended charge separation states are the consequence of the trap state enabled by the antiferromagnetic exchange interaction between the light-induced exciton and the localized 4 fspins of the Nd2+in the proximity. Importantly, this Kondo-like exciton-spin interaction can be modulated by either increasing Nd2+doping concentration that enhances the coupling between the exciton and Nd2+4 fspins as evidenced by elongated carrier lifetime, or by using an external magnetic field that can nullify the spin-dependent exchange interaction therein due to the unified orientations of Nd2+spin angular momentum, thereby leading to exciton recombination at the dynamics comparable to pristine MAPbI3.
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Divalent Anionic Doping in Perovskite Solar Cells for Enhanced Chemical Stability
Abstract The chemical stabilities of hybrid perovskite materials demand further improvement toward long‐term and large‐scale photovoltaic applications. Herein, the enhanced chemical stability of CH3NH3PbI3is reported by doping the divalent anion Se2−in the form of PbSe in precursor solutions to enhance the hydrogen‐bonding‐like interactions between the organic cations and the inorganic framework. As a result, in 100% humidity at 40 °C, the 10% w/w PbSe‐doped CH3NH3PbI3films exhibited >140‐fold stability improvement over pristine CH3NH3PbI3films. As the PbSe‐doped CH3NH3PbI3films maintained the perovskite structure, a top efficiency of 10.4% with 70% retention after 700 h aging in ambient air is achieved with an unencapsulated 10% w/w PbSe:MAPbI3‐based cell. As a bonus, the incorporated Se2−also effectively suppresses iodine diffusion, leading to enhanced chemical stability of the silver electrodes.
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- Award ID(s):
- 1806152
- PAR ID:
- 10063554
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 30
- Issue:
- 34
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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