| dc.description.abstract | This thesis aims to fabricate doped halide perovskite materials (HPM) by using targeted elements, which have provided a dimension beyond structural and compositional modification to achieve desired properties. The doping of alkali metal ions (Li+, Na+, K+, Rb+, and Cs+) in three-dimensional HPM is reviewed to lay a particular focus on advances in synthesis, doping induced changes in optical and electrical properties, and their optoelectronic applications. In addition, advancements in wearable perovskite devices (e.g., solar cells, photodetectors, and light-emitting diodes) concerning their device structures, working mechanisms, and fabrication techniques have been discussed. In our first study, we study the doping of Cs and Rb cations into MAPbBr3 PeNCs to optimize their morphology, crystal structure, and optical properties. It is found that rubidium cations doping can greatly enhance the photoluminescence intensity of the MAPBBr3 PeNCs, whereas cesium cations can improve structural stability owing to the increased valance bond intensity. Secondly, we demonstrated the self-passivation method for the surface defects by introducing potassium (K) or rubidium (Rb) during the colloidal fabrication of PeNCs, leading to much-improved crystallinity, photoluminescence, and improved radiative efficiency. Thirdly, poly (L-lactic acid) (PLLA) nanofibrous membranes embedded with FAPbBr3 perovskite nanocrystals by electrospinning the perovskite and PLLA precursor solution were examined. The resultant PLLA-FAPbBr3 nanofibrous membranes exhibited stability and remained in the water for about 45 days while maintaining their PL peak intensity at 50% of the initial value. Finally, a brief study about flexible photoelectric devices based on halide perovskite NCs was conducted. The future development of perovskite devices based on existing innovative display and lighting technologies was also stated. | en_US |
