Surface passivation via post-treatment with organic reagents is a popular strategy to improve the stability and efficiency of perovskite solar cell. However, organic passivation still suffers from the weak bonding bet...Surface passivation via post-treatment with organic reagents is a popular strategy to improve the stability and efficiency of perovskite solar cell. However, organic passivation still suffers from the weak bonding between organic chemicals and perovskite layers. Here we reported a facile inorganic layer passivating method containing strong Pb–S bonding by using ammonium sulfide treatment. A compact PbS_x layer was in-situ formed on the top surface of the perovskite film, which could passivate and protect the perovskite surface to enhance the performance and stability. Our novel inorganic passivation layer strategy demonstrates great potential for the development of high efficiency hybrid and robust perovskite optoelectronics.展开更多
Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed ...Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI_(3) single crystal detector.Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement,the free hole mobility can be directly calculated to be about 22 cm^(2)·V^(-1)·s^(-1),and the hole lifetime is around 6.5μs–17.5μs.Hence,the mobility-lifetime product can be derived to be 1.4×10^(-4)cm^(2)·V^(-1)–3.9×10^(-4)cm^(2)·V^(-1).The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias,which arises mainly from the inhomogeneous electric field distribution inside the perovskite.The positive space charge density can then be deduced to increase from 3.1×10^(10)cm^(-3)to 6.89×10^(10)cm^(-3)in a bias range of 50 V–150 V.The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals,and is also helpful in obtaining a rough picture of the internal electric field distribution.展开更多
Organic–inorganic hybrid perovskites are quite promising candidates in the field of electromagnetic wave (EMW) absorption due to their unique physicochemical properties. However, it is still a considerable challenge ...Organic–inorganic hybrid perovskites are quite promising candidates in the field of electromagnetic wave (EMW) absorption due to their unique physicochemical properties. However, it is still a considerable challenge to satisfy the light weight, broad bandwidth, and strong absorption properties simultaneously. Herein, the solution of methylammonium lead iodide (MAPbI3) perovskites was infiltrated into the pores of reduced graphene oxide (rGO) aerogels. After drying, a series of MAPbI3/rGO composite aerogel (MGA) materials were synthesized by anchoring the MAPbI3 perovskite nanoparticles to rGO sheets with the assistance of rGO templates. Through the adjustment of component ratios, excellent EMW absorption properties are obtained with the synergistic effects of polarization loss, conduction loss, and multiple reflection and scattering of MAPbI3 and rGO. The porous structure of the aerogel and the suitable group distribution ratio allowed the MGA-4 samples to obtain excellent impedance matching and ultra-low density of ∼ 7.69 mg·cm−3. At a low filling ratio of 15 wt.%, the MGA-4 sample simultaneously achieves highly efficient and broadband EMW absorption performance at a thin thickness. The MGA-4 sample obtained a minimum reflection loss value of −64.35 dB and the effective absorption bandwidth (EAB) value of 5.4 GHz at a thickness of 2.08 mm and a maximum EAB (EABmax) value of 6.2 GHz under 2.22 mm. The MGA-5 sample obtained a maximum EAB value of 6.4 GHz with the thinckness of 2.16 mm. Furthermore, the simulation results of the radar cross-section (RCS) verified the component-optimized composites are capable of achieving excellent EMW attenuation. This paper provides a new approach and valuable reference for the development of hybrid perovskite-based microwave absorption materials with lightweight, ultra-broadband, and strong absorption properties.展开更多
基金the support of the NSFC (Grant 21777096 and 51861145101)Huoyingdong Grant (151046)+1 种基金the support of the Initiative Postdocs Supporting Program (Grant No.BX20180185)China Postdoctoral Science Foundation (Grant No.2018M640387)。
文摘Surface passivation via post-treatment with organic reagents is a popular strategy to improve the stability and efficiency of perovskite solar cell. However, organic passivation still suffers from the weak bonding between organic chemicals and perovskite layers. Here we reported a facile inorganic layer passivating method containing strong Pb–S bonding by using ammonium sulfide treatment. A compact PbS_x layer was in-situ formed on the top surface of the perovskite film, which could passivate and protect the perovskite surface to enhance the performance and stability. Our novel inorganic passivation layer strategy demonstrates great potential for the development of high efficiency hybrid and robust perovskite optoelectronics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12175131 and 11905133)the China Postdoctoral Science Foundation(Grant No.2021M692021)。
文摘Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI_(3) single crystal detector.Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement,the free hole mobility can be directly calculated to be about 22 cm^(2)·V^(-1)·s^(-1),and the hole lifetime is around 6.5μs–17.5μs.Hence,the mobility-lifetime product can be derived to be 1.4×10^(-4)cm^(2)·V^(-1)–3.9×10^(-4)cm^(2)·V^(-1).The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias,which arises mainly from the inhomogeneous electric field distribution inside the perovskite.The positive space charge density can then be deduced to increase from 3.1×10^(10)cm^(-3)to 6.89×10^(10)cm^(-3)in a bias range of 50 V–150 V.The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals,and is also helpful in obtaining a rough picture of the internal electric field distribution.
基金financial support from the National Natural Science Foundation of China(No.52103223)the Natural Science Basic Research Program of Shaanxi(No.2023-JC-YB-413)+2 种基金the Natural Science Foundation of Heilongjiang Province of China(No.YQ2023E027)the Key Laboratory of Functional Molecular Solids,Ministry of Education(No.FMS20230010)the Fundamental Research Funds for the Central Universities(Nos.3072024GH2605,3072024XX2613,and 3072024XX2616).
文摘Organic–inorganic hybrid perovskites are quite promising candidates in the field of electromagnetic wave (EMW) absorption due to their unique physicochemical properties. However, it is still a considerable challenge to satisfy the light weight, broad bandwidth, and strong absorption properties simultaneously. Herein, the solution of methylammonium lead iodide (MAPbI3) perovskites was infiltrated into the pores of reduced graphene oxide (rGO) aerogels. After drying, a series of MAPbI3/rGO composite aerogel (MGA) materials were synthesized by anchoring the MAPbI3 perovskite nanoparticles to rGO sheets with the assistance of rGO templates. Through the adjustment of component ratios, excellent EMW absorption properties are obtained with the synergistic effects of polarization loss, conduction loss, and multiple reflection and scattering of MAPbI3 and rGO. The porous structure of the aerogel and the suitable group distribution ratio allowed the MGA-4 samples to obtain excellent impedance matching and ultra-low density of ∼ 7.69 mg·cm−3. At a low filling ratio of 15 wt.%, the MGA-4 sample simultaneously achieves highly efficient and broadband EMW absorption performance at a thin thickness. The MGA-4 sample obtained a minimum reflection loss value of −64.35 dB and the effective absorption bandwidth (EAB) value of 5.4 GHz at a thickness of 2.08 mm and a maximum EAB (EABmax) value of 6.2 GHz under 2.22 mm. The MGA-5 sample obtained a maximum EAB value of 6.4 GHz with the thinckness of 2.16 mm. Furthermore, the simulation results of the radar cross-section (RCS) verified the component-optimized composites are capable of achieving excellent EMW attenuation. This paper provides a new approach and valuable reference for the development of hybrid perovskite-based microwave absorption materials with lightweight, ultra-broadband, and strong absorption properties.
