大尺寸MAPbI_3单晶的制备及光电性能研究

Preparation and Optoelectronic Properties of Large-scale MAPbI_3 Single Crystals

采用两步气相沉积法制备了大尺寸(150μm左右)高质量的MAPbI_3单晶,并通过对衬底表面修饰来调控晶体的成核位置.从衬底温度、载气流速、时间效应等方面系统探究了影响PbI_2晶体生长的因素.结果表明:该晶体生长的最优条件分别对应为350℃、20sccm、20min.将MAPbI_3单晶放置在空气中50天后,其X衍射特征峰没有明显变化.最后分析该器件的光电特性,发现其开关比高达10~4,响应度为3.8×10~4 A/W,且具有较快的响应速度(上升时间:0.03s;下降时间:0.15s).该MAPbI_3单晶光电探测器将在光电学领域有非常良好的应用.

A large size(about 150μm)high quality MAPbI3 single crystals have been grown by modifying the surface of the substrate to control the nucleation position.Furthermore,the growth factors of PbI2 crystals was studied systematically,mainly including substrate temperature,flow rate of carrier gas,time effect.The results showed that the best conditions for the crystal growth correspond to 350℃,20 sccm and 20 min.In addition,the perovskite single crystalline was measured by XRD when exposed to air for 50 days or more.Although the characteristic peaks were different in size,the crystal did not change as a whole.By analyzing the optoelectronic properties of device,we found that the switch ratio of device is up to 10^4,and its responsivity is 3.8×10^4 A/W.In addition,the device shows a fast response(rise time:0.03 s;fall time:0.15 s).The above shows that our developed MAPbI 3 single crystal photodetector will have a very good application in the field of optoelectronics.