Hey there Abhisek Panda! It's great that you're working on optimizing your perovskite device. Increasing Jsc (short-circuit current density) in Cs0.15FA0.85PbI3 perovskite can be achieved through a few strategies.

Firstly, consider optimizing the perovskite film quality. This involves controlling factors such as precursor stoichiometry, deposition techniques (like spin-coating or vapor deposition), and post-treatment processes (like annealing). Ensuring a uniform and defect-free perovskite film can significantly enhance charge carrier generation and collection, thus boosting Jsc.

Secondly, the interface between layers in your device structure plays a crucial role. Optimize the interface between Cs0.15FA0.85PbI3 and adjacent layers like PCBM and PEI. Proper interfacial engineering can minimize charge recombination and facilitate efficient charge transfer, leading to higher Jsc.

Moreover, consider optimizing the charge transport layers, such as PEDOT:PSS and PCBM. These layers influence charge extraction and transport within the device. Tuning their properties, like thickness and doping concentration, can enhance charge collection efficiency and consequently increase Jsc.

Additionally, pay attention to device fabrication conditions, such as humidity and temperature during film deposition and encapsulation. Suboptimal conditions can lead to defects or degradation, impacting device performance.

Regarding factors affecting lower Jsc, consider issues like film morphology, trap density, interfacial recombination, and electrode contact quality. These factors can limit charge generation, transport, and extraction efficiency, thereby reducing Jsc.

In summary, optimizing perovskite film quality, interfacial properties, charge transport layers, and fabrication conditions can help increase Jsc in your Cs0.15FA0.85PbI3 perovskite device. By addressing these factors systematically, you Abhisek Panda can work towards achieving higher performance. Let me know if you Abhisek Panda need more details on any specific aspect!