| Organic-inorganic semiconductor materials,especially organic-inorganic hybrid perovskite garner enormous attention for a wide range of optoelectronic devices.Due to their attractive optical and electrical properties including high optical absorption coefficient,high carrier mobility,long carrier diffusion length and so on.More importantly,organic-inorganic hybrid perovskites can reduce the industrialization costs,for a variety of:industrial and scientific applications.At present,semiconductor materials are mostly applied to various types of devices in the form of thin films,so the quality of the films directly affects the performance of the devices.In order to make the material fully exert its performance in the device,it is necessary to reduce the defects in the film caused by manufacturing process and improve the film quality.Because the film prepared by solution method,so its possesses a morphology of small crystal grains, many grain boundaries and high sturface roughness.Due to the existence of a large number of defects,the film quality is unstable and the reproducibility is poor.So how to prepare high-quality perovskite film has become a common challenge for researchers.In this paper,three kinds of materials,mixed cations perovskite,mixed halides perovskite and CdI2(AD)were studied.The Pressure-Assisted Space-Confined Solvent-Engineering Method was proposed to study the growth process of the film.And finally to produce a high quality film to obtain high performance optoelectronic devices.The main contents of the paper are as follows:1.The preparation of high-quality MAi-XFAXPbI3 films and its photosensitive properties The MAi,xFAxPbI3 films prepared by the conventional annealing method was spin-coated by one-step method,then the Pressure-Assisted Space-Confined Solvent-Engineering Method was carried out on the prepared films.After PSS procedure,it was found that the crystallinity of the film was obviously improved and the grain size was enlarged,both the flatness and the coverage are improved.But the obtained films have a significant phase separation due to the impurity removal in the crystal growth process,and a heterostructure of MAPbl3/δ-FAPbI3 is formed on films.Photodetectors were manufactured based on this high-quality heterostructure films,and it has been found that the photodetection performance and stability of photodetectors based on this film have been greatly improved.2.The preparation of high-quality MAPb(I0.δBr0.2)3 films and its photosensitive properties.We use Pressure-Assisted Space-Confined Solvent-Engineering Method to grow high-quality mixed halides perovskite thin films.The obtained MAPb(I0.8Br0.2)3 films were highly oriented,pinhole free,with large-scale crystalline grains,high smoothness and crystalline fusion on grain boundaries.And the optical properties of the film are significantly improved.The performance of the photodetector based on this high-quality film is also much improved,the I;gh,/Idark ratio is up to an order of 105,with a photoresponsivity of 3.61× 103 mA/W,and a higher detectivity of 6.42×1012 Jones.3.The preparation of high-quality CdI2(AD)films.The preparation method of the coordination organic-inorganic semiconductor CdI2(AD)film was explored.The quality of the prepared film was optimized from solvents used in the solution,and the PSS method was applied to the growth of high-quality CdI2(AD)films.By adjusting the assisting solvents also achieved the effect of improving the quality of the film,and the photodetection performance was also improved.This result proves that the Pressure-Assisted Space-Confined Solvent-Engineering Method invented by us has certain universality in the high-quality film preparation,this method can be very helpful in making hybrid semiconductor film devices. |
PDF Full Text Request