The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are...The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are identified as crucial solutions. Organic perovskites MAPbI<sub>3</sub> and FAPbI<sub>3</sub>, characterized by their abundance, low cost, and ease of synthesis, are emerging as candidates for study to enhance their competitiveness. It is within this framework that this article presents a comparative analysis of the performances of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites in the context of photovoltaic devices. The analysis focuses on the optoelectronic characteristics and stability of these high-potential materials. The optical properties of perovskites are rigorously evaluated, including band gaps, photoluminescence, and light absorption, using UV-Vis spectroscopy and photoluminescence techniques. The crystal structure is characterized by X-ray diffraction, while film morphology is examined through scanning electron microscopy. The results reveal significant variations between the two types of perovskites, directly impacting the performance of resulting solar devices. Simultaneously, the stability of perovskites is subjected to a thorough study, exposing the materials to various environmental conditions, highlighting key determinants of their durability. Films of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> demonstrate distinct differences in terms of topography, optical performance, and stability. Research has unveiled that planar perovskite solar cells based on FAPbI<sub>3</sub> offer higher photoelectric conversion efficiency, surpassing their MAPbI<sub>3</sub>-based counterparts in terms of performance. These advancements aim to overcome stability constraints and enhance the long-term durability of perovskites, ultimately aiming for practical application of these materials. This comprehensive comparative analysis provides an enlightened understanding of the optoelectronic performance and stability of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites, which is critically important to guide future research and development of solar devices that are both more efficient and sustainable.展开更多
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
文摘The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are identified as crucial solutions. Organic perovskites MAPbI<sub>3</sub> and FAPbI<sub>3</sub>, characterized by their abundance, low cost, and ease of synthesis, are emerging as candidates for study to enhance their competitiveness. It is within this framework that this article presents a comparative analysis of the performances of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites in the context of photovoltaic devices. The analysis focuses on the optoelectronic characteristics and stability of these high-potential materials. The optical properties of perovskites are rigorously evaluated, including band gaps, photoluminescence, and light absorption, using UV-Vis spectroscopy and photoluminescence techniques. The crystal structure is characterized by X-ray diffraction, while film morphology is examined through scanning electron microscopy. The results reveal significant variations between the two types of perovskites, directly impacting the performance of resulting solar devices. Simultaneously, the stability of perovskites is subjected to a thorough study, exposing the materials to various environmental conditions, highlighting key determinants of their durability. Films of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> demonstrate distinct differences in terms of topography, optical performance, and stability. Research has unveiled that planar perovskite solar cells based on FAPbI<sub>3</sub> offer higher photoelectric conversion efficiency, surpassing their MAPbI<sub>3</sub>-based counterparts in terms of performance. These advancements aim to overcome stability constraints and enhance the long-term durability of perovskites, ultimately aiming for practical application of these materials. This comprehensive comparative analysis provides an enlightened understanding of the optoelectronic performance and stability of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites, which is critically important to guide future research and development of solar devices that are both more efficient and sustainable.
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.
