| Thanks to the excellent optical and electronic properties such as high absorption coefficient and long carrier transfer distance, organic metal halide perovskite has been widely used in photovoltaic, photodetector, and laser and was considered to be the next generation of industrial solar cells. However, the organic metal halide perovskite thin films are easily influenced by the environmental factors such as water vapor, which seriously affect the repeatability and stability of the device performance. Studying and mastering the environment-sensing properties and mechanism of organic metal halide perovskite thin films is one of the key issues of developmenting high performance perovskite functional device. Therefore, this paper studied the sensing characteristics of CH3NH3PbIxCl3-x perovskite under various temperature, humidity and ambient conditions by in situ resistance test.Firstly, CH3NH3PbIxCl3-x perovskite thin films were prepared by solution method and thermal evaporation method. By measuring the resistance change of perovskite thin films under different environmental conditions and the characterization of XRD, the effect mechanism of CH3NH3PbIxCl3-x perovskite thin films and water vapor was studied. The results show that the interaction of CH3NH3 PbIx Cl3-x and water respectively through chemical adsorption, generating a hydrate of CH3NH3PbIxCl3-x·H2O and material decomposition stages. In addition, we confirmed that the presence of water has a promoting effect on the thermal decomposition of CH3NH3PbIxCl3-x. The comparison of perovskite thin films prepared by different processes shows that the perovskite thin films with less defects are easier to obtain good humidity stability. At the same time, the resistance response of CH3NH3 PbIx Cl3-x thin films in NH3, NO2, SO2 and other common gases, such as ethanol, acetone and other common solvents, was also tested, can provide reference for the stability study of various kinds of organic metal halide perovskite functional devices. |
PDF Full Text Request