Improving Efficiency And Stability Of 2D Perovskite Solar Cells With Metal Ion Doping

Organic-inorganic hybrid perovskite material has attracted tremendous attention in recent years due to its unique optoelectronic properties.In the past 10 years,the power conversion efficiency?PCE?of perovskite solar cells?PSCs?has been continuously elevated from the initial 3.8%to 25.2%,ascribing to the intensive research efforts in this area.Despite the high PCEs of the laboratory devices,the long-term instability issue of the three-dimensional?3D?perovskite material under heat and humidity hinders its real-world application.In 2014,the structurally distinct two-dimensional?2D?layered perovskite material was introduced as a new class of light absorbing material in PSCs,which significantly improved the device stablity.The PCE of the 2D layered perovskite solar cell devices exhibited relatively lower PCEs,which requires a systematic investigation on each of the functional layers in the device.The main research objective of this thesis is to prepare 2D PSCs with high efficiency and stability.The main research content includes the screening of stable charge transfer layer?CTL?and light absorption layer for the 2D PSC device and the subsequent perfection of each layer through metal ion doping.Besides,the research content also includes the fabrication of inverse opal?IO?structured CTLs and its application in PSC device.The thesis contains 6 chapters as fellows:Chapter 1 briefly introduces the background and basic working mechanism of 2D PSCs.Chapter 2 introduces the fabrication and characterization of 2D PSCs.Chapter 3introduces the Cu doped Ni O film as efficient hole transport layer for 2D PSCs,where it is proposed that the Cu metal ion doping could effectively elevate the Ni vacancy concentration,improve the conductivity of the Ni O film and subsequently enhance the corresponding device PCE.Chapter 4 introduces the Cs doping in the 2D perovskite layer for highly efficient and stable PSCs,where it is evident that Cs ion doping could significantly improve the 2D perovskite film quality and effectively suppress non-radiative recombination,leading to the fabrication of devices with a promissing PCE of13.92%and remarkable stability.Chapter 5 introduces the employment of inverse opal?IO?structured Ni O and Ti O₂ charge transport layers in highly efficient PSCs.Chapter6 concludes the research results and gives outlook.To summarize,based on the careful selection of key materials and the synergistic improvement of bimetallic ions,the conductivity of charge transfer layer is optimized and the quality of light absorption layer is improved,which promises highly efficient and stable 2D PSCs.Our findings pave a new way to fabricate highly efficient and stable PSCs and shed light on the further advancement of the devices based on the 2D perovskite materials...