Research On The Stability And Efficiency Of Perovskite Solar Cells Prepared By All-weather Printing Process

Compared with traditional fossil fuels,solar energy has a prominent position in the next generation of renewable energy due to its infinite supply,eco-friendliness,and safety.Perovskite solar cells,as a highly competitive photovoltaic technology,have attracted widespread attention due to their low cost and excellent photovoltaic performance.However,due to the fact that perovskites have more ionic bond properties than traditional inorganic semiconductors,it is still difficult to achieve both efficient and stable operation under long-term bias voltage and high-temperature actual working conditions.In addition,in the process of preparing perovskite films by printing,the nucleation and crystallization process,which is more difficult to control,may cause lower crystallinity or non-crystalline grain boundaries,which may result in higher defect density and further reduce the ion migration activation energy,leading to greater challenges in improving the efficiency and stability of the devices.Furthermore,when the printing process is applied to the preparation of flexible devices,inevitable mechanical and/or thermal stress during processing,annealing,and operation can cause microcrack extension or interlayer delamination at low fracture energy grain boundaries,resulting in low efficiency and poor mechanical stability.To address the above core issues,this paper aims to prepare high-performance solar cell devices in a low-cost way and focuses on the all-weather preparation of efficient and stable rigid and flexible perovskite solar cells using large-area coating processes.Specifically,it includes the following contents:1.Thermal shock fabrication of ion-stabilized perovskite films.By introducing the thermal shock method in the large-area coating process,the perovskite precursor solution is instantly nucleated and crystallized,transforming into high orientation,continuous,dense,and glossy high-quality perovskite films within a time scale of 0.1 seconds.At the same time,due to the drastic temperature gradient changes in the thermal shock process,Cl-is frozen in the surface lattice under the kinetic effect,forming a compressed surface lattice.Various characterizations of ion migration show that the ion migration in the perovskite films prepared by this method is significantly suppressed,and the ion activation energy is significantly improved.Meanwhile,the defect concentration in the highly crystalline perovskite films prepared by this method were decreased significantly,and the carrier mobility were also increased synchronously.This method provides a new way to utilize strain engineering to regulate the ion stability of perovskites at the lattice level.2.Research on optoelectronic performance,stability,and reliability of thermalshock devices.We further used this large-area coating process to fabricate inverted solar cell devices.The test results showed that the photovoltaic conversion efficiency of the device was increased to nearly 23% after the surface pressure-strained perovskite film was passivated by a compatible large-area process,while the non-radiative voltage loss was only 109 m V.It also greatly improved the comprehensive stability of the perovskite solar cell,and the hysteresis phenomenon directly related to ion migration was not observed even at high temperatures of 363 K.Due to its significantly improved ion stability at high temperatures,its T80 for stable operation under heating conditions exceeded 4000 hours,and it could even be used as a highly stable electroluminescent device.In addition,this device also showed excellent environmental and thermal cycling stability and high reliability,which could be prepared under high relative humidity of up to 90% in the air,realizing the preparation of high-efficiency and longlife perovskite solar cells using a low-cost method.3.Ionogel-perovskite matrix enabling highly efficientand stable flexible solar cells towards fully-R2 R fabrication.We further explored the continuous,scalable,and low-cost preparation of flexible perovskite solar cells in an atmosphere without humidity control using the abovementioned roll-to-roll compatible large-area coating process.To address the decrease in device efficiency and stability caused by strain induced by bending in flexible devices,we prepared a multifunctional ionogel network-modified perovskite polycrystalline film in situ.The ionic liquid and polymer composite network effectively regulated the mechanical properties and passivation effects of the perovskite device,achieving stable efficiency of 21.76% and extremely low open-circuit voltage loss in flexible devices based on a scalable coating process.The significantly enhanced interfacial toughness and rapid self-healing ability at room temperature endowed flexible devices with good operational stability(T90>1336 h),mechanical stability(T90>25000 times,bending radius: 5 mm),and water resistance,breaking the limitations between efficiency,stability,and flexibility in flexible perovskite solar cells.