Interface Regulation And Wearable Application Of Perovskite Solar Cells

In recent years,perovskite solar cells(PSCs)have been rapidly developed due to their excellent optoelectronic properties,and have become the best choice in the new generation thin-film solar cells.To realize the commercial application of wearable electronics,while meeting the performance requirements of the wearable market,it is also necessary to develop a device with lighter weight,better flexibility,even moveable,stretchable and washable,so as to meet the continuous green energy supply demand of various wearable electronic devices.Our work focuses on the improvement of PSCs’ efficiency and wearability based on the performance control and structure design,mainly carried out the following aspects of work:(1)Crystallization and interface engineering of perovskite are the most important factors in achieving high-performance PSCs.An ultrathin Cd Se quantum dots underlayer was construccted via a solution-processable method,which acts as a seed-mediated layer for perfect perovskite film,with both uniform morphology and better absorption capacity.In addition,Cd Se QDs and perovskites form a fully crystalline heterojunction,which is beneficial to minimizing the defect and trap densities.Then,an Ostwald ripening process is adopted to fabricate large-grain,pinhole-free perovskite thin film,by a simple methylammonium bromide treatment.Besides,the first principle is applied and confirms that electrons can move even quicker and more effectively.Due to these treatments,representing a very simple method to simultaneously control perovskite crystallization and optimize the interfaces in PSCs,a maximum power conversion efficiency of15.68 % is achieved,indicating better performance.(2)PSCs have the advantages of being solution-processible,low cost,thin,and mechanically flexible,which makes them ideal candidates for being used in smart clothing.However,existing electron transfer layer(ETL)must be sintered at high temperature,which limits their potential use.Thus,there is a clear motivation to develop low-temperature annealing technologies for ETLs with high crystallinity.Sn O2 nanocrystals were successfully synthesized by conventional hydrothermal method with a grain size of about 60 nm.The prepared low temperature Sn O2 ETL showed high crystallinity,which was beneficial to the growth of high-quality perovskite films.By anti-solvent continuous two-step spin coating,the flexible PSCs were assembled and the device exhibited excellent performance with an efficiency of 17.68 %.It also showed a low hysteresis effect as well as good bending stability,photo stability and thermal stability.(3)Considering the trends towards miniaturization and automation of electronics,increasingattention should be given to self-actuating microenergy technologies.In particular,it is important for these systems to simultaneously possess simple structure,self-powered energy supply,and high power density.Using a facile and ultrafast fabrication approach,a highly efficient walking PSC is constructed as a prototype actuator with a straightforward design but advanced functions.The device demonstrates a high walking speed of 10 mm min-1,excellent mechanical strength(the ability to lift an object 15 times its own weight),and high photoelectric efficiency(17.75 %)as a low-temperature flexible solar cell.The dynamic output of the device during passive heliotropic walking is also evaluated.The maximum output power of the device reaches 215 W m-2.This device shows promise for use as a mobile energy source in various technological applications.(4)Range of power generating approaches such as integrating with clothing,fashion accessories,and textiles allow electronic devices to be charged in environmental friendly ways.Thus stretchable,efficient,stable,and even washable solar cells are required as most decisive and restricting demand to supply continuous wearable energy.A kirigami inspired unique island-chain structure with serpentine interconnects can prevent the photo-active layer of subcells from being subjected to excessive strain.The obtained devices exhibited a high yet stable power output(efficiency of 17.68 %)accompanied by robust cycling performance(87 % of the initial PCE)even after 300 times continuous stretching with a large ratio of 80 %.As textile-compatible power sources,the successfully designed stretchable and moisture-resistant photovoltaics add power-generation functionality to clothing,opening a new avenue for applications as long-term power sources for wearable electronics.(5)Increasing performance demand associated with short lifetime of consumer electronics have triggered a fast growth of electronic waste,leading to serious ecological challenges worldwide.A robust strategy for judiciously constructing flexible PSCs was developed that can be conveniently biodegraded.The key to this strategy is to capitalize on meniscus-assisted solution printing as a facile means of yielding cross-aligned silver nanowires in one-step,which are subsequently impregnated in biodegradable elastomeric polyester.Intriguingly,the as-crafted hybrid biodegradable electrode greatly constrain the solvent evaporation of the perovskite precursor solution,thereby generating fewer nuclei and in turn resulting in the deposition of a large-grained dense perovskite film that exhibits excellent optoelectronic properties with an efficiency of 17.51 %.More importantly,the hybrid biodegradable electrode-based devices also manifest impressive robustness against mechanical deformation and could be thoroughly biodegraded after use.As such,it represents an important endeavor towards environmentally friendly,multifunctional and flexible electronic devices.